3 Nutrition and Dairy Industry Benefits Associated With Promoting
Lowfat Milk: Evidence From the 1989 CSFII
\&
.David L. Pelletier, Annej(enda/1, Laura Kettel Khan, and Alan Mfithios
Folate Intake and Supplement Use in Women of Childbearing Age
Gail E. Gates and Tawni W. Holmes
Trends in Availability of Foods and Nutrients: A Comparison Between
the United States and l!aly, 1961-92
Claire Zizza and Shirley Gerrior
Research Briefs
Factors Associated With the Intake of Dietary Supplements
Rodolfo M. Nayga, Jr. and Debra B. Reed
49 The Diet Quality of Americans: Strong Link With Nutrition Knowledge
Mark Lino, P. Peter Basi otis, Raj enS. Anand, and Jayachandran N Variyam
52 Facts About Childhood Obesity and Overweightness
Center f or Nutrition Policy and Promotion
Research Summat;ies
54 Earnings of Husbands and Wives in Dual-Earner Families
Retirement Prospects of Baby Boomers
Clinical Guidelines: Identification, Evaluation, and Treatment of
Overweight and Obesity in Adults
Regular Items
62
64 Research and Evaluation Activities in USDA
68 Journal Abstracts
70 USDA Food Plans: Cost of Food at Home
71
72 Consumer Prices
Dan Glickman, Secretary
U.S. Department of Agriculture
Shirley R. Watkins, Under Secretary
Food, Nutrition, and Consumer Services
Rajen Anand, Executive Director
Center for Nutrition Policy and Promotion
CarolS. Kramer-LeBlanc, Deputy Executive Director
Center for Nutrition Policy and Promotion
P. Peter Basiotis, Director
Nutrition Policy and Analysis Staff
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Research Articles
3
14
26
Nutrition and Dairy Industry Benefits Associated With
Promoting Lowfat Milk: Evidence From the 1989 CSFII
David L. Pelletier, Anne Kendall, Laura Kettel Khan, and Alan Mathias
Folate Intake and Supplement Use in Women of
Childbearing Age
Gail E. Gates and Tawni W. Holmes
Trends in Availability of Foods and Nutrients: A Comparison
Between the United States and Italy, 1961-92
Claire Zizza and Shirley Gerrior
Research Briefs
43 Factors Associated With the Intake of Dietary Supplements
49
52
Rodolfo M. Nayga, Jr. and Debra B. Reed
The Diet Quality of Americans: Strong Link With Nutrition
Knowledge
Mark Lino, P. Peter Basiotis, Rajen S. Anand, and Jayachandran N. Variyam
Facts About Childhood Obesity and Overweightness
Center for Nutrition Policy and Promotion
54 Earnings of Husbands and Wives in Dual-Earner Families
56 Retirement Prospects of Baby Boomers
59 Clinical Guidelines: Identification, Evaluation, and Treatment of
Overweight and Obesity in Adults
62 Federal Statistics: Eating and Exercise
64 Research and Evaluation Activities in USDA
68 Journal Abstracts
70 USDA Food Plans: Cost of Food at Home
71 Alaska and Hawaii Food Plans: Cost of Food at Home
72 Consumer Prices
Volume 12, Number 1
1999
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David L. Pelletier1
Anne Kendall1
Laura Kettel Khan 1
·
3
Alan Mathios2
1
Division of Nutritional Sciences, Cornell
¥niversity
Department of Policy Analysis and Management,
fomell University.
Current affiliation: Division of Nutrition and
Physical Activity, Center for Chronic Disease
Prevention and Health Promotion, Centers for
Disease Control and Prevention, Atlanta, GA.
1999 Vol. 12 No. 1
Research Articles
Nutrition and Dairy Industry
Benefits Associated With
Promoting Lowfat Milk:
Evidence From the 1989 CSFII
The dairy industry spends about $225 million each year promoting its
products, but historically, it has resisted explicit promotion of lowfat milk.
This study examines the potential nutritional and industry benefits associated
with greater use of lowfat milk by the U.S. population. The 1989 Continuing
Survey' of Food Intakes by Individuals (CSFII) was used to examine the
association between types of milk, intake of lipids and calcium, and quantity
of milk consumed. Results show that compared with whole milk drinkers,
lowfat milk drinkers obtain less fat, saturated fat, and cholesterol from milk.
However, lowfat milk drinkers are more likely than their counterparts to
exceed the recommended levels of fat and saturated fat from all food
sources. Lowfat milk drinkers consumed one-third to one-half more milk
on the recalled day than whole-milk drinkers consumed. These results are
consistent with other evidence that the dairy industry may derive economic
benefits from promoting lowfat milk; the nutritional benefits are less clear.
Additional study is warranted in this area: the effects of milk type on milk
intake and dietary substitutions. Nutrition education should continue to
promote specific dietary changes within the context of the total diet.
or the past few decades,
public-private partnerships
have emerged as an important
element of nutrition
and public health strategies (14,17).
Similarly, the Institute of Medicine has
recommended the negotiation of such
partnerships as an important part of
national, State, and local efforts to improve
the diets of the U.S. population ( 14).
Voluntary partnerships are particularly
attractiye as a means for implementing
national nutrition policy because of the
size of the food industry, the intensity
of its marketing strategies, and the limited
degree to which government regulation
and promotion can be applied in this
sector. The 5 A Day for Better Health
Campaign is one example of such a
partnership (9).
Unlike the 5 A Day Campaign that aligns
nutrition objectives and industry objectives
(i.e., both seek to promote greater
consumption of fruits and vegetables), a
perceived conflict exists between dairy
industry objectives and nutrition objectives
as they relate to dietary fat. Dairy
foods (as a class) are relatively high in
total and saturated fats, and they contribute
a large share of these nutrients (as well
as calcium) in the American diet. For
instance, analysis of a national sample
revealed that whole milk, natural and
3
processed cheese, and lowfat milk (all
types combined) contribute 33 percent
of the saturated fats and 21 percent of
total fats in the diets of 2- to 5-year-old
children ( 15 ). The same study estimated
that the average intakes of fat and saturated
fats by these children could be
reduced to 30 percent and 10 percent
of calories, respectively (corresponding
to the upper levels as recommended for
individuals), if lower fat versions of
these three product categories were
adopted. Such estimates make dairy
products an attractive target for nutrition
education and behavior change programs,
especially in light of the apparent simplicity
of changing to lower fat versions
of milk. Recent work by the Center for
Science in the Public Interest confirms
that it may be feasible to induce a substantial
population-level shift toward
!-percent milk and skim milk through
intensive community-based promotions
(2).
At the time of the report on Improving
America's Diet and Health ( 14), the
Committee on Dietary Guidelines
Implementation of the Food and Nutrition
Board believed that the dairy industry
had inadequately promoted lowfat versions
of dairy products, citing concerns about
product image, price incentives, and
labeling definitions. Since then, a number
of changes have occurred at the national
level to reduce those concerns and create
incentives for the industry to promote
lowfat milk. These changes include
marked reductions in the U.S. Department
of Agriculture's (USDA) support prices
for dairy producers, corresponding declines
in government-held surpluses of
butter and c~eese, more export opportunities,
intense competition in the beverage
industry for low-calorie products, and
redefinition of "lowfat" milk by the
Food and Drug Administration (FDA)
( 11 ). The familiar "moustache"
4
advertisements for milk and related
promotional materials (7) are indicators
of this shift in marketing strategy at the
national level.
Despite this encouraging trend in industry
advertising at the national level, much
more needs to be done at State and local
levels where the majority of funds for
dairy promotion are spent and where
more intensive, innovative promotional
work can occur. The industry currently
issues a mandatory assessment ("checkoff')
against producers, representing
15 cents per 100 pounds of milk, onethird
of which supports national promotional
efforts; two-thirds supports State
and local efforts. In 1993 this assessment
generated about $75 million for use at
the national level and $150 million for
use at State and local levels. Most of
these funds continue to be used for
generic promotion programs, rather than
lowfat promotion, despite evidence of
diminishing returns in some markets
( 13) and differential effects on the sale
of whole, lowfat, and skim milk ( 12 ).
This paper presents some findings on
(1) the quantitative contribution of dairy
products to the nutrient intakes of children
and adults, with a special emphasis on
fluid milk; and (2) the relationship between
types of milk (whole vs. lowfat)
and amount of milk consumed. The first
of these results is needed to estimate the
magnitude of the effect (on nutrient intake)
that might be expected from lowfat milk
promotion efforts. The second of these
results is of great interest to the dairy
industry, because of the industry's concern
that promoting lowfat milk might
decrease product sales. These analyses,
together with interviews with members
of dairy promotion boards, were undertaken
at the request of the New York
State Department of Health to identify
opportunities for partnering with the
industry to promote lowfat milk. The
results are described at greater length
elsewhere ( 11 ).
Methods
This study uses data from the 1989
Continuing Survey of Food Intakes
by Individuals (CSFII), a multistaged,
stratified probability sample that is representative
of the 48 contiguous States. The
sample consisted of 4,876 respondents.
Sample sizes for African Americans and
Hispanics were too small for most age
categories to provide separate analyses,
hence results are presented for all groups
combined. Race, age, income, education,
and region are controlled for in multiple
regression analyses. Sample weights
were used in all analyses to make inferences
to the general population of the
48 contiguous States.
Dietary data were collected using a
24-hour recall conducted in person by a
trained interviewer. Two additional days
of dietary data were collected by a foodrecord
method, with no probing for portion
sizes and methods of preparation. The
two methods yielded significant differences
in the estimate of the amount of
milk consumed each day: data from the
dietary records collected on the second
and third days suggested lower intakes.
The 24-hour recall data are used here;
we believe the recall data more accurately
represent actual consumption.
The CSFII data set contains codes for
422 dairy items, grouped for this analysis
into an overall dairy category and seven
subgroups: Milk, yogurt, milk drinks,
ice cream, ice milk, frozen yogurt, and
cheese. People who reported using more
than one dairy product or type of milk
on the recalled day are included in all
applicable categories for the purpose
of estimating the percentage of people
Family Economics and Nutrition Review
Table 1. Sample sizes and percent reporting1 various types of milk, 1989 CSFII
Age and Percent reporting
gender Total n Any dairy Any milk Whole 2-percent !-percent Skim
Males
1-5 324 93.2 81.6 34.1 37.6 2
6-11 299 91.9 82.6 47.6 37.6
12-15 114 95.7 81.3 27.0 42.7
16-18 120 75.6 68.7 24.8 34.3
19-24 146 80.7 51.7 27.5 17.4
25-44 600 74.1 56.3 21.3 23.9 3.1 8.0
45-64 328 73.9 53.2 22.1 18.2 3.6 9.3
65+ 336 77.1 62.1 24.5 19.4 6.1 12.1
Females
1-5 325 94.8 84.9 46.8 35.6
6-11 290 86.6 71.9 31.4 27.5
12-15 102 87.1 60.0 27.8 30.6
16-18 122 80.8 61.5 27.9 26.6
19-24 160 82.2 54.1 29.6 20.0
25-44 759 77.1 59.5 19.8 23.2 4.4 12.1
45-64 429 70.0 58.3 22.7 21.9 2.3 11.4
65+ 422 85.6 71.6 25.9 27.6 5.7 12.4
~Sample sizes refer to the number of observations in the data set; "percent reporting" cells reflect sample weights.
Cells are blank when the sum of the 1-percent and skim columns is less than 20 cases.
consuming a product. People not reporting
the type of milk consumed were excluded
from the analysis. Our paper focuses
on fluid milk because of the interest in
promoting lowfat versions of this product,
which includes milk consumed as a
beverage or as an easily recalled ingredient
in some dishes (e.g., with breakfast cereal)
but generally does not include milk used
in more complex dishes (e.g., casseroles).
We used descriptive statistics to examine
the percentage of respondents using any
dairy product on the recalled day: Any
type of milk; and whole, 2-percent, 1-
percent, and skim milk. Because these
categories are not mutually exclusive
1999 Vol. 12 No.1
and many respondents can report more
than one category on a given day or in a
3-day period, the samples overlap. Thus
such "cross-drinkers" are found in 12
percent of the adult female sample and
11 percent of the adult male sample, based
on a subanalysis of the 3-day dietary
data for each person. Cross-drinkers are
included in some descriptive statistics
(table 1) but are excluded from the
regressions, which require that individuals
be assigned to only one category of milk.
Descriptive statistics are provided on
the contribution of these dairy product
categories to total fat, saturated fat,
cholesterol, and calcium intake on the
recalled day. The dietary data are com-pared
with the recommended levels of
total fat (no more than 30 percent of
calories), saturated fat (no more than 10
percent of calories), and cholesterol (no
more than 300 milligrams) based on the
Dietary Guidelines for Americans ( 16)
and compared with the recommended
levels of calcium based on the 1989
Recommended Dietary Allowances (8).
We use multiple regression to estimate
the statistical effect of type of milk on
milk intake while controlling for potential
socioeconomic confounders. This analysis
was conducted among 25- to 44-yearold
adults for whom total sample sizes
are greatest and the samples reporting
5
6
Whole milk and
2-percent milk are
the more common
forms consumed
at all ages ....
1-percent and skim milk are sufficient
to support these analyses. Separate
regressions were conducted to contrast
whole milk with 2-percent, with 1-percent
and skim combined, and with alllowfat
versions combined (2-percent, 1-percent,
and skim). The 1-percent and skim-milk
drinkers were combined because of
small sample sizes; they were analyzed
only when at least 20 cases were in a
given age/gender group to reduce the
influence of random error on parameter
estimates. Regression analyses were
conducted with only those respondents
who reported consuming any type of
milk on the recalled day. Hence the
results presented here refer to the portion
of the population that consumes milk.
All statistics were calculated with SAS
(version 6), and proportional sample
weights were used.
Results
About 70 to 96 percent of the sample
reportedly consumed some type of dairy
product on the recalled day (table 1). A
somewhat lower percentage, 52 to 85
percent, reportedly consumed some type
of fluid milk. Among milk drinkers,
roughly half reportedly consumed whole
milk, and most of the others reported
drinking 2-percent milk. Whole milk
and 2-percent milk are the more common
forms consumed at all ages and are consumed
by roughly similar proportions
of the sample at each age. About 11 to
18 percent of respondents in the three
oldest age categories (25 to 44, 45 to 64,
and 65+) reported consuming 1-percent
or skim milk on the recalled day, with
skim milk being more common than
1-percent milk.
Whole milk provides 9 to 10 grams of
total fat and about 6 grams of saturated
fat for males and 6 to 9 grams of total
fat and 4 to 6 grams of saturated fat for
females (table 2). This represents about
10 to 12 percent of total daily fat intake
and 15 to 22 percent of saturated fat
intake in most age/gender groups.
(Results are not shown.) As expected,
the quantity of fat and saturated fat provided
by milk decreases considerably
from whole milk to skim milk for all
age/gender groups. Milk as a total category
provides roughly half of the fat
and saturated fat that comes from all
dairy foods combined. (Results are not
shown.)
The difference in fat and saturated fat
intake across the four types of milk
suggests that fat intake might be reduced
if whole-milk drinkers switched to lower
fat versions and did not start other dietary
substitutions. Actually, the use of lower
fat milks seems to be associated with
considerable substitution, as shown in
the "Pct>30%" and "Pct>lO%" rowsthe
percentage of persons whose total
fat and saturated fat intake (from all
sources) was greater than recommended
levels on the recalled day. Compared
with the consistent gradient across the
types of milk noted earlier, no consistent
gradient is obvious in the percentage
of respondents meeting the recommendations
for fat and saturated fat. For
instance, in five of the six age/gender
groups, 2-percent milk drinkers exceed
the recommendations for total fat and
saturated fat by a higher percentage,
compared with whole-milk drinkers.
The same is true for the saturated fat
recommendation. One-percent and skimmilk
drinkers have values similar to or
less than those for whole-milk drinkers
in many age/gender groups.
The results for cholesterol follow a
pattern similar to those for fat and saturated
fat, with stepwise gradients in the
quantity of cholesterol derived from
milk, across the four types of milk and
Family Economics and Nutrition Review
Table 2. Nutrient intake, by milk type, 1989 CSFD
Age and Milk t~2e consumed b~ males Milk t~2e consumed b~ females
grams Whole 2-percent 1-percent Skim Whole 2-percent 1-percent Skim
Total fat
25-44
Grams 9.6 7.1 5.7 0.9 6.8 5.6 4.4 0.5
Pct>30% kcals1 73 66 87 55 63 65 76 70
45-64
Grams 9.6 6.7 2 0.5 6.1 9.7 0.5
Pet> 30% kcals 1 51 73 85 72 76 68
65+
Grams 9.2 5.8 2.3 0.6 8.8 5.0 2.5 0.5
Pct>30% kcals1 71 85 73 63 67 81 58 65
Saturated fat
25-44
Grams 6.0 4.4 3.6 0.6 4.2 3.5 2.8 0.3
Pet> I 0% kcals 1 67 75 80 87 65 70 84 79
45-64
Grams 6.0 4.2 0.3 3.8 5.6 0.3
Pet> I 0% kcals 1 49 79 80 73 72 55
65+
Grams 5.7 3.6 1.4 0.4 5.5 3.0 1.6 0.3
Pet> 1 0% kcals 1 76 82 67 62 58 81 57 71
Cholesterol
25-44
Grams 39 28 22 9 28 22 17 5
Pct>300 mg1 29 32 25 57 31 30 31 37
45-64
Grams 39 26 5 25 22 5
Pct>300mg1 14 11 6 16 12 6
65+
Grams 37 22 9 6 36 19 10 5
Pct>300mg1 31 19 20 33 27 43 15 27
Calcium
25-44
Grams 342 450 663 642 243 356 516 315
Pct<2/3 RDA 1 34 41 52 39 37 47 48 38
45-64
Grams 343 422 363 217 354 332
Pct<2/3 RDA 1 36 40 40 32 40 43
65+
Grams 328 365 270 427 315 310 300 349
Pct<2/3 RDA 1 56 49 18 44 49 34 52 38
~Percentage of respondents whose intake of nutrie?ts from all ~ood sources on the recall day did not meet the recommended level.
Cells are blank when the sum of 1-percent and skim columns IS less than 20 cases.
1999 Vol. 12 No. 1
7
Milk intake, by milk type, 1989 CSFII
Grams per day
700
600
500
400
300
200
100
0
Males
~
v~;
700
600
500
~
v~;
~
~
~
400
300
200
100
0
1-5 6-11 12-15 16-18 19-24 25-44 45-84 65+ 1-5 6-11
Age groups
.Whole milk
a less consistent gradient for percentage
of persons exceeding the recommendation
based on all foods consumed on the
recalled day. The results for calcium
show no consistent gradient across the
types of milk consumed and age/gender
groups, although there is a tendency
toward higher calcium intakes among
!-percent and skim-milk drinkers,
compared with whole-milk drinkers.
Is there a relationship between the type
and amount of milk consumed? For all
males except the 12 to 15 age groups,
2-percent milk drinkers report higher
milk consumption on the recalled day
than whole-milk drinkers reported (figure) .1
Among 25- to 44-year-old men, milk
consumption is greatest among !-percent
drinkers and second highest among
1The !-percent and skim-milk categories are
omitted when the sample size is less than 20 for
any given age group.
8
~ 2-percent milk 01-percent milk
skim-milk drinkers. There is no consistent
relationship between milk type and quantity
consumed for men 45 to 64 years or 65
years and older. Likewise, for females,
there is no consistent relationship across
the age groups, although the 25- to 44-
year-olds who consumed lower fat
versions of milk have consumed more
grams of milk, compared with wholemilk
drinkers.
Analysis of the characteristics of different
milk drinkers revealed that lower fat
milk is differentially consumed by older
age groups, Whites (versus non-Whites),
those with higher incomes, those living
in the Northeastern United States, and
those with more years of education
(data not shown). For this reason, we
used multiple regressions to examine
the statistical effect of milk type on
milk volume after controlling for these
potential confounding factors (table 3).
Females
~
~
~ ~
~ v~;
~
12-15 16-18 19-24 25-44 45-64 65+
Age groups
!&l Skim milk
The milk-type variable is positive and
statistically significant for each of the
three contrasts, for males as well as
females.
The size of the difference between
whole-milk drinkers and various lower
fat milk drinkers is substantial (table 4).
Compared with their intake of whole
milk, males' intake of other types of
milk is hlgher: 2-percent milk, 18 percent
higher; !-percent and skim milk, 102
percent hlgher; and 2-percent, !-percent,
and skim milk combined is 55 percent
higher. The corresponding intake values
for females are 58 percent, 75 percent,
and 62 percent, respectively. In all
cases, adjusting for socioeconomic
differences across milk types leads to
an increase in the effect estimates,
rather than a decrease.
Family Economics and Nutrition Review
Table 3. Multiple regression equations testing the effect of milk type on milk volume while controlling for
potential confounders (25- to 44-year-olds), 1989 CSFD
Whole vs. lowfat1 Whole vs. 2-percent Whole vs. !-percent and skim
Gender and characteristics B P-value B P-value B P-value
Males
Age (years) -14.00 0.0001 -11.35 0.0001 -10.33 0.002
Income ($ x 1 ,000) -0.12 0.08 -0.89 0.14 -0.28 0.003
Education (years) -1.13 0.48 -0.51 0.68 0.66 0.78
Race (White vs. other) 108.94 0.02 73.33 0.04 89.11 0.10
Region (Northeast vs. other) 2.36 0.95 -202.24 0.0001 95.34 0.02
Milk type2 170.16 0.0001 54.90 0.04 314.42 0.0001
Females
Age -3.00 0.05 -1.19 0.39 -3.25 0.12
Income -0.66 0.08 -1.64 0.0001 0.05 0.92
Education -0.60 0.63 -0.99 0.34 -1.56 0.41
Race 4.32 0.87 -22.75 0.28 -9.50 0.79
Region -23.08 0.30 25.58 0.20 -61.88 0.04
Milk type2 139.63 0.0001 129.63 0.0001 167.12 0.0001
1 Lowfat refers to 2-percent, !-percent, and skim milk combined.
2yalues indicate the difference (in grams) in consumption between whole-milk drinkers (reference group) and the lowfat categories. Positive values indicate
greater consumption in low fat categories.
Discussion
This paper provides empirical results
that may help nutrition, public health,
and dairy promotion board representatives
evaluate the potential benefits of explicitly
promoting lowfat milk. For nutrition
and public health practitioners, it is
important to know the contribution that
milk consumption makes to total daily
intake of key nutrients (fat, saturated
fat, cholesterol, and calcium), the extent
to which lowfat milk consumption affects
that contribution, and the extent to which
use of lower fat milks is associated with
lower total fat and saturated fat intakes.
For dairy promotion boards, it is important
to know what effect, if any, promotion
1999 Vol. 12 No.1
of lowfat milk may have on total milk
sales.
This paper reveals that, for most adult
age/gender groups, whole milk provides
about 6 to 10 grams of total dietary fat
and 4 to 6 grams of saturated fats, compared
with less than 1 gram of total fat
or saturated fat for skim-milk drinkers.
This represents roughly 10 to 12 percent
of total fat and 15 to 22 percent of saturated
fat in the daily diet. These figures
suggest that we might expect a substantial
reduction in daily fat and saturated fat
intake if whole-milk drinkers switched
to skim milk, used the same quantity
of milk each day, and made no other
dietary substitutions .. This paper provides
evidence, however, that use of lower fat
milks is associated with substantially
higher volumes of intake among 25- to
44-year-olds (55 to 62 percent for all
lowfat versions combined), representing
a type of dietary substitution. Tills volume
effect may offset some of the fat-related
benefits of switching to lower fat milk
but represents a positive finding with
respect to calcium and other nutrients
in milk. We also found that, compared
with whole-milk drinkers, lowfat milk
drinkers are as likely or even more
likely to exceed the recommendations
for dietary fat when all food sources are
considered. Results suggest that ilietary
substitutions may negate some or all of
9
... the use of lower
fat versions of milk
is associated with
greater intakes.
10
Table 4. Estimates of the effect of milk type on milk volume for 25- to
44-year-olds (adjusted consumption derived from regressions), 1989
CSFll
Observed consumption Adjusted consumption
Percent Percent
Gender and
milk type
Grams increase over Grams increase over
consumed whole milk consumed whole milk
Males
Whole
Lowfat1
2-percent
1-percent and skim
Females
Whole
Lowfat
2-percent
1-percent and skim
308
411
371
506
223
303
299
310
2
33
21
64
36
34
39
308
478
363
622
224
363
353
390
55
18
102
62
58
75
~Lowfat refers to 2-percent, !-percent, and skim milk combined.
Reference group.
the nutritional benefits of consuming
lowfat milk.
We believe it is of interest that the percentage
of fat, saturated fat, and cholesterol
derived from cheese is similar to
that provided by whole milk-among
the 25 to 30 percent who report using
cheese on the recalled day ( 11 ). Moreover,
the percentage of these nutrients
derived from pizza, among the 5 to 10
percent reporting pizza on the recalled
day, is 3 to 5 times greater than the
contribution from whole milk for those
older than 20 years ( 11 ). However,
cheese was reported by only about half
as many people as those reporting milk;
pizza was reported by an even smaller
number of people. The results nonetheless
indicate the potential for substitutions
to negate or overcompensate for the
positive effects of lowfat milk consumption
on total fat and saturated fat intake,
even when the substitutions take place
within the dairy category. U.S. milk
supply data (macro level) provide further
evidence of product substitutions; the
sustained shift toward 2-percent milk
since the mid-1970's has been accompanied
by a 50-percent increase in cheese
use (6), in part reflecting the growth in
fast-food and prepared-food sectors.
One of the most provocative findings
from this study, from the perspective
of forming partnerships with dairy promotion
boards, is this: the use of lower
fat versions of milk is associated with
greater intakes. This occurred in all age
groups for males (except 12- to 15-yearolds)
and in five of the seven age groups
for females. Findings from the multiple
Family Economics and Nutrition Review
regressions suggest that among 25- to
44-year-olds (for whom sample sizes
are adequate) this relationship is not due
to confounding by socioeconomic factors:
the magnitude of the statistical effect
is greater after adjusting for potential
confounders. The New York State Dietary
Survey that used a food frequency
instrument supports our findings ( 10,11 ).
Similar results also are evident in 18- to
24-year-old women in the 1989-91 CSFII
(4), women aged 18 and over in the
1990-91 CSFII ( 3 ), and in the communitybased
campaign by the Center for Science
in the Public Interest (CSPI) (2). Significantly,
the CSPI found that total milk
sales rose by 15 percent in the month
after the campaign and 25 percent 1 year
later. Together, these results provide
consistent evidence that an economic
incentive may exist for the dairy industry
to promote lowfat milk.
Several methodological limitations are
relevant in making inferences about the
potential effects of switching to lowfat
milk on milk volume and on total daily
intake. First, data in this study are crosssectional
and may reflect self-selection
effects. That is, those now using lower
fat milk may differ in many ways from
those using whole milk, including the
other dairy and nondairy components
of their diets. And these traits may have
preceded their switch to lowfat milk.
Although the methods used here control
for some of the potential confounding
factors, they do not control for all potential
confounding factors, and they do not
address the possibility of reverse causality
(i.e., that those with high fat intakes
and/or high milk intakes may have
switched to lowfat milk, rather than
the switch in the type of milk causing
an increase in milk intake). Longitudinal
and experimental designs would provide
more convincing evidence of the net
1999 Vol. 12 No. 1
effects of switching to lower fat milk
and associated substitutions.
Second, although dietary substitutions
are a widely recognized class of behaviors
( 18 ), our approach for estimating substitutions
relies upon examination of grouplevel
data (table 2), rather than multiple
regression. We used group-level data
because of the inherent limitations of
24-hour recalls as estimates of habitual
intake and substitutions. Using the 24-hour
recalls in multiple regression analyses
to investigate substitutions would likely
lead to a large overestimate of the degree
of substitution in the habitual diet. For
example, most people are unlikely to
consume milk, cheese, yogurt, cottage
cheese, and ice cream all in 1 day, but
all of these foods may be part of their
habitual diet. Using group averages
overcomes this problem but generates
results that refer to group tendenciesnot
individual behavior.
Third, this study refers to milk drinkers'
consumption patterns of 1989, which
may differ from today' s consumption
patterns. Moreover, according to these
analyses about 40 percent of 25- to 44-
year-olds reported no milk consumption
on the recalled day, roughly similar to
the 30 percent seen in the fulll989-91
CSFII based on 3 days of observation
for each subject (5). The factors associated
with switching to lowfat milk and with
the quantity of milk consumption may
be quite different from the factors associated
with the practice of consuming
or not consuming milk habitually. Both
sets offactors are of great interest-from
an industry and a public health perspectiveand
are worthy of more detailed investigation
using the more recent 1994-96
CSFII data. In particular, it would be
instructive to apply econometric approaches
to investigate these relationships
and to address the limitations we noted
( 1 ). This is relevant to note: the twostage
regression analysis of the 1989
CSFII data provided results similar to
those reported here ( 11 ).
Our study provides evidence that the
explicit promotion of lowfat milk may
produce economic benefits for the dairy
industry. Ironically, the nutritional benefits
of such promotion (with respect to
meeting the dietary fat recommendations)
are less convincing in this study, because
of the possibility of dietary substitutions.
Additional studies of these substitution
effects and milk volume effects are
warranted, as is continued educational
emphasis on the importance of the total
diet. Practitioners may want to use
these encouraging findings to initiate
or strengthen their dialog with dairy
promotion boards at the State and local
levels, where two-thirds of the dairy
industry's promotion dollars are spent.
Acknowledgments
We thank the New York State Department
of Health, Division of Nutrition, for
suggesting this project and providing
the funding.
11
12
References
1. Briscoe, J., Akin, J., and Guilkey, D. 1990. People are not passive acceptors of
threats to health: Endogeneity and its consequences. International Journal of
Epidemiology 19:147-153.
2. Center for Science in the Public Interest. 1997 (January).1% or Less Yes. 1% or
Less Update. Center for Science in the Public Interest. Washington, DC.
3. Guthrie, J.F. 1996. Dietary patterns and personal characteristics of women
consuming recommended amounts of calcium. Family Economics and Nutrition
Review 9( 3 ):33-49.
4. Hampl, J.S. and Betts, N.M. 1995. Comparison of dietary intake and sources
of fat in low- and high-fat diets of 18- to 24-year-olds. Journal of the American
Dietetic Association 85:893-897.
5. Life Sciences Research Office. 1995. Third Report on Nutrition Monitoring in
the United States, Vol. 2. Report prepared for the Interagency Board for Nutrition
Monitoring and Related Research.
6. Milk Industry Foundation. Milk Facts: 1994 Edition. Washington, DC.
7. National Fluid Milk Processor Promotion Board. 1995. Milk! What a Surprise!
Surprising Facts About Milk Booklet.
8. National Research Council, Subcommittee on the Tenth Edition of the RDAs,
Food and Nutrition Board. 1989. Recommended Dietary Allowances (1Oth ed. ).
National Academy Press, Washington, DC.
9. Neil, K. and Allensworth, D.D. 1994. A model to increase consumption of fruits
and vegetables by implementing the Five-a-Day initiative. Journal of School Health
64(4):150-155.
10. Ogden, C.L. 1994. New York State Dietary Survey Dairy Food Analysis. Report
prepared for New York State Department of Health. Division of Nutritional Sciences,
Cornell University, Ithaca, NY.
11. Pelletier, D.L., Kendall, A., and Mathios, A. 1996. Lowfat Milk Promotion:
Opportunities Created by A New Policy Environment. Report Prepared for the New
York State Department of Health. Division of Nutritional Sciences and Department
of Consumer Economics and Housing, Cornell University, Ithaca, NY.
Family Economics and Nutrition Review
12. Reberte, C. and Kaiser, H.M. 1996. Impact of generic fluid milk advertising on
whole, lowfat, and skim milk demand. National Institute for Commodity Promotion
Research and Evaluation 96-01:1-7. Cornell University, Ithaca, NY.
13. Reberte, C., Kaiser, H.M., Lenz, J.E., and Forker, 0 . 1995. Generic advertising
wearout: The case of the New York City Fluid Milk Campaign. National Institute
for Commodity Promotion Research and Evaluation 95-02:1-9. Cornell University,
Ithaca, NY.
14. Thomas, P.R. (Ed.). 1991. Improving America's Diet and Health (pp. 202-203).
National Academy Press, Washington, DC.
15. Thompson, F.E. and Dennison, B.A. 1994. Dietary sources of fats and cholesterol in
US children aged 2 through 5 years. American Journal of Public Health 84:799-806.
16. U.S. Department of Agriculture and U.S. Department of Health and Human
Services. 1990. Nutrition and Your Health: Dietary Guidelines for Americans
(3rd ed.). Home and Garden Bulletin No. 232.
17. U.S. Department of Health and Human Services, Public Health Service. 1991.
Healthy People 2000: National Health Promotion and Disease Prevention Objectives.
18. Von Braun, J. and Puetz, D. 1993. Data Needs for Food Policy in Developing
Countries. International Food Policy Research Institute, Washington, DC.
1999 Vol. 12 No.1 13
Gail E. Gates
Oklahoma State University
Tawni W. Holmes
Oklahoma State University
14
Folate Intake and
Supplement Use in Women
of Childbearing Age
Data from the 1994-95 Continuing Survey of Food Intakes by Individuals
were analyzed to determine folate intake and supplement use by women
of childbearing age (11 to 50 years old). We identified the primary food
sources of folate and mean folate intake from two nonconsecutive 24-hour
recalls and examined characteristics of supplement users of B vitamins.
Top sources of folate were ready-to-eat cereals, citrus fruits and juices,
grain mixtures, and yeast breads. Mean dietary folate was 215 ± 3 J.Lg.
On a daily basis, one of four women consumed supplements containing
B vitamins. Thirty-two percent of women consumed at least 400 J.Lg folates
from food and/or daily supplements. Compared with nonusers, daily suppl&
ment users were more likely to be White, older, more educated, frequent
exercisers, and have higher income. Results suggest that nutrition educators
may be more successful encouraging women to consume additional servings
of fortified-grain products rather than encouraging women to add folate-rich
foods or supplements to their diet.
eural tube defects are serious
birth defects that can result
in infant mortality or serious
disability. Each year in the
United States about 4,000 infants are
born with neural tube defects such as
spina bifida, which has the third highest
lifetime cost of any birth defect ( 11 ).
Thus, there is continual need to identify
modifiable risk factors that can prevent
this defect. Adequate folic acid status
is potentially an ideal modifiable risk
factor, because folate coenzymes function
metabolically in the synthesis of RNA,
DNA, and protein in the developing
fetus (27,33,37).
To prevent neural tube defects, women
need to achieve optimal folate status
before pregnancy occurs, because the
neural tube forms and closes during the
first month of pregnancy. Increasing
folate intake by diet and supplements
before conception and in the first 6 weeks
of pregnancy has been shown to protect
against the occurrence of neural tube
defects (6,13,28,29).
Adequate folate intake is especially
important for women with a history of
a pregnancy with a neural tube defect.
Recurrence rates for women with a previously
affected pregnancy are about
1 0 to 15 times higher than those for
the general population (39). However,
95 percent of infants with neural tube
defects are born to women without
a family history of the defects ( 4 ).
Because about hal{ of pregnancies are
unplanned or rnistimed (20), adequate
folate intake is important for all
women who can become pregnant.
Family Economics and Nutrition Review
Women in their childbearing years
consume less than the recent recommendations
for folate: at least 400 J.lg
per day of folic acid to reduce the risk
of neural tube defects (9, 10 ). Data from
the Third National Health and Nutrition
Examination Survey (NHANES) and
the 1989-91 Continuing Survey of
Food Intakes by Individuals (CSFII)
have shown that most women of childbearing
age consumed about half the
recommended amount offolates ( 1,38).
Subar et al. ( 45) found that 93 percent
of women surveyed in the NHANES II
consumed less than the recommendation.
In the 1986 CSFII, less than 10 percent
of women met the recommended 400 J.lg
folate per day, and only about 30 percent
of low-income women and 50 percent
of higher income women met the 1989
Recommended Dietary Allowance
(180 J.lg) (30) from food sources (5) ..
This study examines folate intakefrom
food and supplement use-of a
sample of households with women of
childbearing age. Understanding the
existing patterns of folate intake and
characteristics of women who consume
supplements will allow researchers and
others to evaluate the potential effects
associated with changes in diet or
supplement use among women.
Subjects and Methods
We examined the foods consumed by
2,086 women of childbearing age (11
to 50 years old) who completed two
24-hour dietary recalls in the U.S.
Department of Agriculture's (USDA)
1994-95 CSFII. The CSFII provides
information on nutrient intakes and a
number of demographic, socioeconomic,
and personal characteristics. To identify
Participants, the survey incorporates a
stratified, multistage sampling plan.
1999 Vol. 12 No. 1
Subjects are noninstitutionalized individuals
grouped by gender, age, and
income level. Details of the study design
and recruitment of CSFII participants
are described in detail elsewhere (49).
Food Sources
USDA food codes classify foods into
11 major food groups: Milk and milk
products; meat, poultry, and fish; eggs;
legumes; nuts and seeds; grain products;
fruits; vegetables; fats; sugars and
sweets; and beverages. The USDA
food codes also identify 59 subgroups
within 8 of the major food groups. For
example, vegetables are divided into 8
subgroups (white potatoes; dark-green
vegetables; deep-yellow vegetables;
tomatoes; lettuce; green beans; corn,
green peas, and lima beans; and other
vegetables). Eggs, legumes, and nuts
and seeds do not contain subgroups.
To determine whether to use a major
food group or subgroup for this analysis,
we identified the five foods in each
subgroup most frequently consumed
by the women of childbearing age who
were included in this study. The CSFII
Survey Nutrient Data Base was used
to determine the amount of folate in a
serving of each identified food (49). If
the amount of folate in the foods in the
subgroups was similar, we used only
the major food group. For example,
skim milk and whole milk contain
about the same amount offolate (12 J.lg),
so we reported all fluid milk as one
group.
If the amount of folate in the subgroups
was substantially different, we used
each subgroup separately. For example,
ready-to-eat cereals ( 44 J!g) and rice
(2 J.lg) were analyzed as separate grain
subgroups. We selected 38 food groups
and subgroups from 70 possible groups
and subgroups. The total amount of
folate in each of the selected groups
was divided by the total folate intake
from all foods (45), and foods were
ranked by percentage contribution to
dietary folate intake (table 1). To determine
the percentage of women who
consumed each food, we grouped those
who consumed any amount of the food
and those who did not consume the
food during the two 24-hour recalls.
Statistical Analysis.
Using SPSS software (42), we compared
differences in mean dietary
folate intake among women based on
their descriptive characteristics. T-tests
compared folate intake by ethnic origin,
weight-loss diet, smoking status, and
use of food stamps. Analysis of variance
(ANOV A) with Scheffe range tests
compared folate intake by race,
pregnancy/lactation status, supplement
use, household income (expressed as
a percentage of the Federal poverty
index), and exercise frequency. Pearson
coefficients were used to correlate folate
intake from food with mean grams of
foods consumed, level of education,
energy intake, and body mass index
(BMI).
We described the characteristics of
women who used supplements containing
B vitamins (daily, every so often, and
never) using ANOV A and Chi-square
analyses. We used normalized 2-day
sample weights (49), and we reported
means and standard error of the mean
(SEM). Differences were considered
statistically significant at the p<O.Ol
level-a more conservative level than
standard practice-to compensate for
the effects of the large sample size and
complex design ( 49 ).
15
Results
Food Sources
For 11- to 50-year-old women in this
study, the major sources of folate were
ready-to-eat cereals, citrus fruits and
juices (predorllinately orange juice),
grain rllixtures such as pizza, and yeast
breads (table 1). Ready-to-eat cereals
contributed 20 percent of total folates
to the women's diet; citrus fruits and
juices, 8 percent; grain rllixtures,
7 percent; and yeast breads, 6 percent.
Some of the other top contributors of
folate (e.g., milk, nonalcoholic beverages,
and white potatoes) are not rich sources
of this vitamin, but these foods were
consumed by most women during the
two nonconsecutive 24-hour dietary
recalls (64 to 95 percent). Other foods
that are naturally rich sources of folate
(e.g., dark-green vegetables and liver)
did not contribute as much folate to the
diet, because few women consumed
these foods.
The foods that correlated most strongly
with folate intake were ready-to-eat
cereals, citrus fruits and juices, fluid
milk, and legumes, such as beans (refried
and pinto). For example, women
who consumed less than 120 l!g folates
ate almost no (0.4 g) ready-to-eat cereals;
however, women who consumed at
least 400 l!g folates ate, on average,
46.8 g of ready-to-eat cereals per day.
(Data are not shown.)
Folate Intake by Characteristics
Overall, only 8 percent of the women
of childbearing age consumed more
than 400 l!g folate per day (the new
recommendation) (figure). Mean folate
intake was 215±31-lg, and median intake
was 1891-lg. (Data are not shown.)
About half ( 4 7 percent) of the women
consumed less than the 1989 RDA of
16
Table 1. Sources of folate in the diets of U.S. women of childbearing
agel and correlation between grams of food consumed and folate
intake, 1994-95 CSFII
Percent of
Percent of women who
Food group2 total folate3 consumedf~ r
Ready-to-eat cereals 19.7 34.6 0.59***
Citrus fruits and juices 7.6 36.7 0.35***
Mixtures mainly grains 6.5 60.7 0.08***
Total yeast breads and rolls 6.2 82.4 0.11***
Mixtures mainly meat, poultry, fish 5.1 56.4 0.09***
Other vegetables (including brewer's yeast) 4.5 62.5 0.13***
Legumes 4.5 22.0 0.25***
Fluid milk 4.4 67.6 0.36***
Nonalcoholic beverages 4.1 95.2 0.09***
White potatoes 4.0 63.5 0.00
Lettuce 3.5 42.3 0.15***
Cake, cookies, pastries, pies 3.3 56.1 0.10***
Dark-green vegetables 3.1 16.7 0.17***
Other fruits, mixtures, juices 3.0 50.0 0.20***
Com, lima beans, ~n peas 2.3 20.3 0.12***
Eggs 2.3 28.6 0.03
Crackers, popcorn, pretzels, com chips 1.8 43.4 0.15***
Tomatoes . 1.6 57.5 0.13***
Nuts, seeds 1.3 13.9 0.11 ***
Quick breads, pancakes, french toast 1.3 36.4 0.09***
Alcoholic beverages 0.9 13.8 0.06***
Beef 0.9 35.7 0.02
Cheese 0.8 52.4 0.09***
Green beans 0.8 13.1 0.04
Poultry 0.8 40.5 -0.05
Milk-based desserts 0.7 25.0 0.12***
Sugar 0.7 69.1 0.06***
Organ meats (e.g., liver) 0.5 0.8 0.11 ***
Deep-yellow vegetables 0.5 21.7 0.11***
Pasta 0.5 13.5 0.07***
Fish, shellfish 0.5 13.7 0.01
Yogurt 0.4 7.0 0.11 ***
Rice 0.4 19.5 0.05
Frankfurters, sausages, luncheon meat 0.3 40.6 -0.03
Fat 0.3 72.0 0.11***
Pork 0.2 23.6 -0.01
Lamb, veal, game 0.1 1.6 0.01
Dried fruits 0.0 2.2 0.14***
~Women II to 50 years old who comp.leted two nonconsecutive24-hourrecalls; n=2,086.
Food groups and subgroups that provided 99 percent of the sample's folate intake.
3The total amount of folate in each group was divided by the total folate intake from all foods consumed by
all women during the two 24-hourrecalls.
4Percentage of women who consumed any amount of the food during the two 24-hourrecalls.
***Significant correlation between grams of food consumed and folate intake, p ~ 0.001.
Family Economics and Nutrition Review
Dietary folate intake (J.J.g) of women 1 11 to 50 years old, 1994-95 CSFII
~9 folate from food
1Women who completed two nonconsecutive 24-hour recalls.
180 ~g folate per day from food sources.
(Data are not shown.) Also, analysis
of folate intake by the women's characteristics
showed that Blacks had lower
intakes than Whites had (table 2). Women
who were breast-feeding consumed
more folate from their diet than other
women consumed. Results also revealed
that subjects with higher incomes, those
who did not receive food stamps, and
nonsmokers consumed more folate than
did their counterparts. Women's folate
intake was not statistically different
based on several characteristics: Ethnic
origin, exercise frequency, BMI (not
shown), and whether the women followed
a weight-loss diet. However,
further analysis showed that dietary
folate was related positively to energy
intake (r=.42, p < 0.001).
Supplement Use
Daily, about one-fourth (27 percent)
of the women consumed a dietary
1999 Vol. 12 No. 1
supplement containing folate, and 15
percent occasionally consumed this
supplement. Only 9 women reported
consuming a separate folic acid supplement;
all other supplement users took
a multivitamin orB-complex vitamin.
Women who took daily supplements
containing B vitamins consumed significantly
more folates from food than
did women who occasionally or never
consumed supplements (table 3). Of
the 161 women who consumed at least
400 ~g folates from food, 42 percent
also took daily supplements. In all, 32
percent (n=661) of the total sample met
the recommendation by diet and/or daily
consumed supplements. (Data are not
shown.)
Women who consumed supplements
daily were significantly more likely to
be older and more educated than were
women who never took supplements.
The foods that
correlated most
strongly with folate
intake were readyto-
eat cereals, citrus
fruits and juices,
fluid milk, and
legumes, such as
beans (refried and
pinto).
17
Table 2. Differences in mean folate intake (j.ig), by demographic
characteristics of women 11 to 50 years old, 1 1994-95 CSFll
Characteristic N Mean±SEM p
Race 0.001
White 1601 219.6±3.42
Black 284 188.5 ± 7.23
Other 201 214.9 ± 8.32
·
3
Origin NS
Non-Hispanic 1851 213.1 ± 3.0
Hispanic 235 228.8± 8.9
Reproductive status <0.001
Pregnant 47 249.0 ± 20.o2
Lactating 33 337.8 ± 34.13
Not pregnant or lactating 2006 212.1 ± 2.92
Receiving food stamps <0.001
Yes 269 182.1 ± 7.12
No 1817 219.8±3.13
Income (% of poverty index) <0.001
<130% 432 197.9±6.22
130-350% 861 208.6±4.22
>350% 793 231.0±5.03
Smoking status 0.001
Smoker 749 201.8± 4.62
Nonsmoker 1337 222.3 ± 3.73
Following a weight-loss diet NS
Yes 145 207.2± 10.8
No 1941 215.5 ± 3.0
Exercise frequency NS
Daily 294 209.4± 7.5
5-6 times a week 162 239.5 ± 11.6
2-4 times a week 539 219.7 ± 5.3
Once a week 194 . 223.0 ± 10.6
1-3 times a month 153 203.3 ± 8.5
Rarely 744 208.5±4.9
1Women 11 to 50 years old who completed lwo nonconsecutive24-hourrecalls; n=2,086.
2•3Values in the same column with different superscript numbers are significantly different, p < 0.01 .
NS = not significant.
18
Those women who consumed supplements
daily were also more likely to
be White, be pregnant or lactating, have
higher income, and be more frequent
exercisers. However, they were less
likely than women who never consumed
supplements with folate to receive food
stamps. Frequency of supplement use
was not related significantly to women's
energy intake, BMI, ethnic origin,
smoking status, and weight-loss diet
status.
Discussion
Three approaches to increasing folate
intake in women are to increase their
consumption of folate-rich foods, add
folic acid to fortified grain products
they consume, or encourage women to
take supplements containing folic acid
( 14,27,31,35,38). Our study provides
results that address all three approaches.
Food Sources
In our study, we found that the foods
which provided the most folate for
women of childbearing age are similar
to the major sources of folates reported
in earlier national studies; however, the
foods appear in a different order. Our
results show that ready-to-eat cereals
provide about 20 percent of the folate
consumed by these women. The top 10
contributors of folate (when regrouped
according to USDA food groups) for
all adults in NHANES II were citrus
fruit and juice, bread, cold cereals,
legumes, green salad, fluid milk, eggs,
alcoholic beverages, coffee and tea, and
liver (45). Top contributors of folate for
women who participated in the 1987-88
Nationwide Food Consumption Survey
were vegetables; ready-to-eat cereals;
meat, fish, poultry; grains; other foods;
desserts and snacks; orange juice; other
beverages; milk; and fruit (38). The
Framingham Study showed that the top
Family Economics and Nutrition Review
Table 3. Frequency of intakes of vitamin B supplement, by demographic characteristics of women 11 to 50
years old, 1994-95 CSFD
Frequency of supplement use
Daily (n=567) Every so often (n=303) Never (n=l216) p
Mean±SEM Mean±SEM Mean±SEM
Folate from food (Jlg) 240.1 ± 5.i 212.1 ± 6.92 203.9 ±3.72 <0.001
Age (years) 32.6 ± 0.41 29.8±0.62 29.4± 0.32 <0.001
Education (years) 13.8 ± 0.11 13.6±0.21 12.8 ± 0.12 <0.001
Energy (kcal) 1765 ±26 1756 ± 34 1692± 18 NS
BMI (kg/m2
) 26.8±0.6 25.7 ±0.7 27.7 ±0.5 NS
N % N % N %
Race <0.001
White 475 83.8 237 78.2 889 73.0
Black 51 9.0 37 12.2 197 16.2
Other 41 7.2 29 9.6 131 10.8
Origin NS
Non-Hispanic 514 90.7 263 86.8 1074 88.2
Hispanic 53 9.3 40 13.2 143 11.8
Reproductive status <0.001
Pregnant 38 6.7 2 0.7 7 0.6
Lactating 22 3.9 2 0.7 10 0.8
Not pregnant or lactating 507 89.4 299 98.7 1199 98.6
Receiving food stamps <0.001
Yes 52 9.2 24 7.9 193 15.9
No 515 90.8 278 92.1 1024 84.1
Income (% of poverty index) <0.001
<130% 90 15.8 46 15.2 296 24.3
131-350% 231 40.7 125 41.4 505 41.5
>350% 247 43.5 131 43.4 415 34.1
Smoking status NS
Smoker 214 37.7 115 38.0 421 34.6
Nonsmoker 353 62.3 188 62.0 796 65.4
Following a weight-loss diet NS
Yes 47 8.3 21 6.9 77 6.3
No 519 91.1 282 93.1 1139 93.7
Exercise frequency <0.001
Daily 83 14.6 35 11.6 176 14.5
5-6 times a week 42 7.4 27 8.9 92 7.6
2-4 times a week 172 30.3 88 29.0 279 22.9
Once a week 67 11.8 31 10.2 96 7.9
1-3 times a month 32 5.6 36 11.9 85 7.0
Rarely 171 30.2 86 28.4 488 40.1
1
•2V'llues in the same row with different superscripts are significantly different, p < 0.01.
NS = not significant.
1999 Vol. 12 No.1 19
20
. .. 27 percent of women
of childbearing age
consumed supplements
containing B vitamins
daily; these women
consumed more folate
than did women
who did not take
supplements.
food sources of folates for elderly subjects
were citrus fruit and juice, cold
cereals, lettuce, dark-green vegetables,
bread, other vegetables, grain mixtures,
fruits, and milk (47).
The richest food sources of folates in
the U.S. food supply are liver, readyto-
eat cereals, legumes, and dark-green
vegetables (2,45). Few women in our
study ate these folate-rich foods, the
exception being-ready-to-eat cereals .
Other foods, such as orange juice,
contain moderate amounts of folates
but are major contributors to the diet
because of the frequency and quantity
with which they are consumed (2).
An important point to make is this:
nutrient databases (including the USDA
database used in this study) are believed
to provide an inaccurate estimate of
folate intake. The database values are
thought to underestimate actual folate
content, because of the limitations of
traditional analytical methods used in
generating the food composition data
for folate ( 18 ).
For women to receive all of the needed
folate from food sources, they need to
consume at least the minimum number
of servings from each food group, as
recommended by the Food Guide
Pyramid ( 17,48), and select good sources
of folates within each food group
( 5,23,33 ). For example, according to
the 1989-91 CSFII, about one-third
of women who consumed folate-rich,
ready-to-eat cereals met the 400 jlg
folate recommendation; less than 5 percent
of women who did not consume
cereal met the recommendation ( 38).
Krebs-Smith et al. (23) found that less
than 1 percent of women in the United
States consumed the recommended
number of servings from all food groups;
only 27 percent consumed the recommended
number of grain products.
Beginning in January 1998, enriched
cereal-grain products in the United
States were fortified to provide 140 jlg
per 100 g of product ( 17 ). This amount
of fortification is estimated to add about
100 jlg folic acid per day to the average
U.S. diet (22,31,46). The Food and
Drug Administration (~DA) allows
breakfast cereals to be fortified with
folic acid up to 400 jlg per serving, but
this is being monitored to determine how
widespread this practice becomes ( 16).
Several recent studies explored the
potential benefits of fortifying grain
products with folic acid. Folic acid
from fortified foods was more effective
in increasing the concentration of
red blood cell folate than equivalent
amounts of naturally occurring folate
( 18). Pfeiffer et al. (32) provided evidence
of effective absorption of folic
acid that is added to grain foods in a
light meal. Their conclusion: folic acid
absorbed from fortified foods should
improve the folate status of the
population.
Two studies of the potential benefits of
folic acid fortification ( 34,46) recently
estimated that the level of fortification
recently approved by the FDA would
increase the percentage of the population
who consume at least 400 g folate to
about 50 percent. Daly et al. estimated
that this level of fortification would
decrease the incidence of neural tube
defects by 50 percent ( 14 ). However,
because many women limit energy
intake and grain consumption, the
influence of fortification may be less
in this high-risk group than in other
groups.
Family Economics and Nutrition Review
Folate Intake by Characteristics
We found that women with higher
energy intakes consume more folate;
however, women who report following
a weight-loss diet consume the same
amount of folate as women who did
not acknowledge following such a diet.
This indicates that women on weightreduction
diets may select more foods
that are good sources of folates. However,
the significant correlation between
energy and folate intake indicates that
women who restrict their energy intake
(even if they do not acknowledge following
a weight-loss diet) are less likely
than their counterparts to consume
enough folate. Other researchers found
that the chance of having an inadequate
folate intake is greater for women
with the following characteristics:
Low socioeconomic status, poor eating
habits, stringent dieting for weight loss,
abuse of drugs or alcohol, and smoking
cigarettes (5,21,33,36). We also found
that smokers consumed less folate than
nonsmokers, and lower income women
consumed significantly less folate than
was the case for higher income women.
Supplement Use
In our study, we found that 27 percent
of women of childbearing age consumed
supplements containing B vitamins
daily; these women consumed more
folate than did women who did not take
supplements. About 25 percent of the
women in the 1992 and 1987 National
Health Interview Surveys consumed
supplements daily (40,41,44). Similar to
our study, the studies of other researchers
show that most adults take one broadspectrum
vitamin/mineral supplement
rather than a single nutrient (7,25,43 ).
The National Health Interview Surveys
also found that daily supplement use
was highest among Whites, those with
higher incomes, and those with more
than a high school education (40,41,44j.
A study of the Dutch population found
1999 Vol. 12 No. 1
that age, social class, alternative food
habits, smoking, and dieting were all
related to the use of supplements ( 15 ).
However, we did not find significant
relationships between dieting or energy
intake and how often the women used
supplements.
Women in our study who took supplements
daily consumed significantly
more folate in their diets than did women
who took supplements less often or
never. The mean intake for all groups
was, however, less than the recommended
amount of folate. Women in the National
Health Interview Survey who took
supplements had diets that were significantly
more healthful (lower in fat and
higher in fiber, calcium, and vitamins
A, C, and E) than non-users had (40).
Others reported similar findings
( 3, 7,24,26).
Supplemental folic acid in doses up
to 1 ,000 J.Lg per day is considered nontoxic
to healthy adults (8,18). Folic
acid in supplements is about twice as
available as naturally occurring folates
because folic acid can be absorbed
intact, while folates must be broken
down before absorption ( 19,37). The
folic acid in supplements may be most
beneficial to women who limit their
dietary selection: such as women who
avoid folate-rich foods or restrict their
energy intake (39). Providing supplementation
to the target group is likely
to cause the least harm to others ( 35 ).
Despite the effectiveness and safety of
folic acid supplements, this approach
probably will have only a small influence
on decreasing the incidence of neural
tube defects because most women are
unlikely to take a supplement before they
become pregnant ( 14,27). A recent study
in London found that only 3 percent of
pregnant women had taken folic acid
supplements before conception when it
would have been most beneficial ( 12 ).
Implications
Our study provides evidence, from a
recent national survey, that can be used
to help nutrition educators and policymakers
in addressing inadequate folate
intake by women of childbearing age.
Increasing folate intake by encouraging
women to add foods that are naturally
rich in folate is a challenge for nutrition
educators. Perhaps, a more successful
approach is to encourage women to
substitute good sources of folate for
low-folate choices (e.g., orange juice
instead of apple juice) or consume an
additional serving of fortified grain
products rather than add a folate-rich
food such as a dark-green vegetable
that few women eat.
Encouraging all women of childbearing
age to take supplements containing
folic acid is another approach to improving
folate status in this high-risk
group. Our findings confirm the results
of other studies on supplement use;
women who take supplements are less
likely to need additional folate than
women who do not take supplements.
Future research should identify the best
strategies to use when shaping nutrition
interventions to increase women's
intake of foods that are naturally rich
or fortified with folates or to increase
women's use of folic acid supplements.
In addition to having information on
the foods that are being consumed and
the demographic characteristics that
influence supplement use, we need to
understand better the behaviors and
environmental factors that shape food
intake and supplement use. Then interventions
and nutrition education programs
can be designed that result in
increased intake of folates.
21
Acknowledgment
This project was funded in part by the
Oklahoma Agricultural Experiment
Station project OKL0/2283.
22
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7. Bowerman, S.J.A. and Harrill, I. 1983. Nutrient consumption of individuals taking
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20. Grimes, D.A 1986. Unplanned pregnancies in the US. Obstetrics and Gynecology
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21. Houghton, L.A., Green, T.J., Donovan, U.M., Gibson, R.S., Stephen, A.M., and
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22. Kelly, P., McPartlin, J., Goggins, M., Weir, D.G., and Scott, J.M. 1997.
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23. Krebs-Smith, S.M., Cleveland, L.E., Ballard-Barbash, R., Cook, D.A., and
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1999 Vol. 12 No. I 23
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25. Levy, A.S. and Schucker, R.E. 1987. Patterns of nutrient intake among dietary
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27. McNulty, H. 1997. Folate requirements for health in women Proceedings of the
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28. Milunsky, A., Jick, H., Jick, S.S., Bruell, C.L., MacLaughlin, D.S., Rothman,
K.J., and Willett, W. 1989. Multivitamin/folic acid supplementation in early pregnancy
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29. MRC Vitamin Study Research Group. 1991. Prevention of neural tube defects:
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of folate from fortified cereal-grain products and of supplemental folate consumed
with or without food determined by using a dual-label stable-isotope protocol.
American Journal of Clinical Nutrition 66:1388-1397.
33. Picciano, M.F., Green, T., and O'Connor, D.L. 1994. The folate status of
women and health. Nutrition Today 29:20-29.
34. Romano, P.S., Waitzman, N.J., Scheffler, R.M., Pi, R.D. 1995. Folic acid
fortification of grain: An economic analysis. American Journal of Public Health
85:667-673.
35. Rush, D. 1994. Periconceptual folate and neural tube defect. American Journal
of Clinical Nutrition 59:511S-516S.
36. Sauberlich, H.E. 1995. Folate status of the U.S. population. In L.B. Bailey (Ed.),
Folate in Health and Disease (pp. 171-194). Marcel Dekker Inc., New York, NY.
37. Sauberlich, H.E., Kretsch, M.J., Skala, J.H., Johnson, H.L., and Taylor, P.C.
1987. Folate requirement and metabolism in nonpregnant women. American Journal
of Clinical Nutrition 46: 1 016-1028.
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38. Schaller, D.R. and Olson, B.H. 1996. A food industry perspective on folic acid
fortification. Journal of Nutrition 126:761S-764S.
39; Scott, J.M., Weir, D.G., and Kirke, P.N. 1995. Folate and neural tube defects. In
L.B. Bailey (Ed.), Folate in Health and Disease (pp. 329-360). Marcel Dekker Inc.,
New York, NY.
40. Slesinski, M.J., Subar, A.F., and Kahle, L.L. 1996. Dietary intake of fat, fiber
and other nutrients is related to the use of vitamin and mineral supplements in the
United States: The 1992 National Health Interview Survey. Journal of Nutrition
126:3001-3008.
41. Slesinski, M.J., Subar, A.F., and Kahle, L.L. 1995. Trends in use of vitamin and
mineral supplements in the United States. Journal of the American Dietetic Association
95:921-923.
42. SPSSfor Windows (Version 7.5). 1997. SPSS, Inc., Chicago.
43. Stewart, M.L., McDonald, J.T., Levy, A.S., Schucker, R.E., and Henderson,
D.P. 1985. Vitamin/mineral supplement use: A telephone survey of adults in the
United States. Journal of the American Dietetic Association 85:1585-1590.
44. Subar, A.F. and Block, G. 1990.Use of vitamin and mineral supplements:
Demographics and amounts of nutrients consumed. The 1987 Health Interview
Survey. American Journal of Epidemiology 32:1091-1101.
45. Subar, A.F., Block, G., and James, L.D. 1989. Folate intake and food sources in
the US population. American Journal of Clinical Nutrition 50:508-516.
46. Tucker, K.L., Mahnken, B., Wilson, P.W.F., Jacques, P., and Selhub, J. 1996.
Folic acid fortification of the food supply: Potential benefits and risks for the elderly
population. Journal of the American Medical Association 276: 1879-1885.
47. Tucker, K.L., Selhub, J., Wilson, P.W.F., and Rosenberg, I.H. 1996. Dietary
intake pattern relates to plasma folate and homocysteine concentrations in the
Framingham Heart Study. Journal of Nutrition 126:3025-3031.
48. U.S. Department of Agriculture, Human Nutrition Information Service. 1992.
The Food Guide Pyramid. Home and Garden Bulletin No. 252.
49. U.S. Department of Agriculture, Human Nutrition Information Service. 1995-96.
Continuing Survey of Food Intakes by Individuals: 1994-95.
1999 Vol. 12 No.1 25
Claire Zizza
University of North CarolinaChapel
Hill
Shirley Gerrior
Center for Nutrition Policy
and Promotion
26
Trends in Availability of
Foods and Nutrients:
A Comparison Between
the United States and Italy,
1961-92
The Mediterranean diet is of interest for its health-promoting qualities. The
purpose of this study is to better define this diet and to compare it with the
U.S. diet. We examined U.S. and Italian food-balance sheet data for 1961-92.
Per capita per year food estimates show less available whole milk and white
potatoes in both countries, less eggs and red meat in the United States, and
less grain in Italy. Italy had higher per capita estimates for grains, cheese,
oils, vegetables, and noncitrus fruits, while the United States had higher
estimates for dairy foods, citrus fruits, eggs, and sugars and sweeteners.
Nutrient levels increased for both countries, except for lower carbohydrate
levels in Italy. Vitamin A, thiamin, riboflavin, niacin, and iron levels were
higher for the United States; vitamin C, calcium, phosphorus, and pota$ium
levels were higher for Italy. The considerable changes in the diets of both
countries in the past 30 years have implications for health, in particular, the
incidence of coronary heart disease and other diseases with acknowledged
nutritional etiology.
[QJ uring the early 1960's,
people living in the Mediterranean
area had some of
the highest life expectancies
and lowest rates of coronary heart disease,
certain cancers, and other chronic
diseases in the world. Unable to attribute
these favorable health statistics to
educational level, financial status, or
health care expenditures, nutrition
researchers have focused on the diet
in this area (23 ). The role of the Mediterranean
diet in the prevention of coronary
heart disease was first described
by Keys in the 1950's (11). Keys showed
that Italian men living in Naples in the
early 1950's had diets in which fat
contributed 20 percent to their total
energy; whereas, a comparable American
group had diets in which fat contributed
40 percent of their energy. He demonstrated
that higher fat diets were associated
with higher concentrations of serum
cholesterol in men and consequently
with a higher risk of atherosclerosis
(9). Keys and his coworkers initiated
in the early 1950's the Seven Countries
Study that lasted for more than 20 years.
This landmark study confirmed his
previous findings: dietary fat influences
levels of human serum cholesterol that
influence the risk: of coronary heart
disease ( 10 ).
Family Economics and Nutrition Review
The desire to preserve traditional diets
likely to foster good health prompted
the World Health Organization (WHO),
the Food and Agriculture Organization
(FAO) Collaborating Center in Nutritional
Epidemiology at Harvard School
of Public Health, the WHO Regional
Office for Europe, and Old ways Preservation
& Exchange Trust to develop
the Mediterranean Food Guide Pyramid
(fig. 1) (23) . These organizations
depicted the Mediterranean diet as a
graphic similar to the Food Guide
Pyramid released by the U.S. Department
of Agriculture (fig. 2) (20). The
Mediterranean Food Guide Pyramid
depicts a general sense of the relative
proportions and frequency of servings
of foods and food groups that constitute
the Mediterranean diet (23 ).
The term "Mediterranean diet" has
been broadened to include primarily
plant-based diets with olive oil as the
major source of fat. At least 16 countries
along the Mediterranean Sea in which
this dietary pattern was possible are
Egypt, Morocco, Syria, Tunisia, Turkey,
Algeria, Greece, Albania, Israel, Spain,
Italy, France, Croatia, Lebanon, Libya,
and Malta (23 ).
The purpose of this study is to better
define the Mediterranean diet and to
compare it with the American diet in
terms of food use and nutrient contributions.
We examined U.S. and Italian
food-balance sheet data, the best available
source of information to examine
dietary trends over time. Thus, the data
are often used for international comparisons
( 11 ). We chose Italy to represent
the Mediterranean area because
food composition and edible portion
data were available for this country.
Within and between country data on
trends for foods, nutrients (food energy,
1999 Vol. 12 No. 1
Figure 1. Mediterranean Diet Pyramid
OI.MOa.
FIWTS VEGITAIUS
IWDS. PASTA. RKt. COUSCOUS. POUNTA.IUI.GUI.
0111£1 GRAINS. ANO POTATOES
Copyright 1994 0/dways Preservation & Exchange Trust.
Figure 2. USDA Food Guide Pryamid
Fols. OilS. It SW881s7 USE SPAIIIHGLY •
d
... ..·.. :. .. . ... ..."". ..... : ... .. .
Mill<. Yo, gu~~ • • Meat Poulry, Filtl,
lr Ctlees8 Group • • ii." 2·3 SEIMIIGS • • Drylr B NeaUnl!s ,G Erogugps .
• ." 2-3 SEIYIN8S
• 0
.. .0 . . . . . . .
Wine in
Modvation
FruiGioup
.~ .........
Btead, cereal,
Rlce,lr Pasla Group
I-11SOVIN8S
27
protein, carbohydrate, and fat; five
vitamins, and four minerals) and sources
of food nutrients were calculated and
compared. Adequate vitamin A and
vitamin C prevents night blindness and
scurvy, respectively. Both are important
antioxidants. Adequate thiamin
prevents beriberi, and in addition to it,
riboflavin and niacin are involved in
energy metabolism. Calcium and phosphorus
are important for their structural
functions in bone. Iron is important in
preventing iron-deficiency anemia, and
potassium is also important in transportation
across cell membranes and in the
metabolism of energy.
In addition, we investigated whether
the idealized Mediterranean diet still
existed and the changes that may have
occurred to this dietary pattern. By
quantitatively examining the similarities
and differences between the
two countries' food supplies, we are able
to discuss the feasibility of implementing
in the United States the Mediterranean
diet as a guidance model.
Methods
The nutrient content of the U.S. and
the Italian food supply was calculated
as similarly as possible for 1961-92.1
Generally, both sets of data were estimated
by multiplying the amount of
each food consumed by the amount of
food energy and other nutrients in the
edible portion of food. The other nutrients
were carbohydrate, protein, fat,
vitamin A, ascorbic acid, thiamin, riboflavin,
niacin, calcium, phosphorus,
iron, and potassium. The data on U.S.
food per capita were converted to kilograms
for ease of comparison. Results
1The year ranges are 1961-65, 1966-70, 1971-75,
1976-80, 1981-85, and 1986-92.
28
for each nutrient for all the foods were
totaled, and amounts per capita per day
were generated. An interactive system2
written in Foxpro, a relational database
management program, was used to
calculate each set of values of nutrients
per capita per day. This system, maintained
by the USDA's Center for Nutrition
Policy and Promotion (CNPP),
contains nutrient estimates from as far
back as 1909. These estimates are updated
on a continual basis to reflect the
most up-to-date food composition.
Two databases for each country were
needed to calculate nutrient per capita:
one on food per capita and another on
nutrient composition. The USDA's
Economic Research Service (ERS)
annually calculates U.S. food per capita
values for most commodities. The U.S.
Department of Commerce's National
Marine Fisheries Service provides fish
and shellfish values. The USDA's
Agricultural Research Service (ARS)
provides nutrient composition data.
Italian food per capita values were
obtained from FAO, and the nutrient
database was based on the Italian
National Nutrition Institute's (INN)
Tabelle di Composizione degli Alimenti3
(2).
Food Database Development
Food-balance sheet data, also referred
to as food supply, food availability,
disappearance data, and consumption
are accounts of food supplies that
"disappear" into the national marketing
system. The estimates of food are
referred to as "disappearance data"
because of the method by which they
are derived. Supply tables are constructed
from data on production, imports, and
beginning -of-the-year inventories;
2-rhe system was writt~n by FU Associates, Ltd.
~Arlington, VA).
Food Composition Table.
whereas, utilization tables are from
data on exports, year-end inventories,
and nonfood uses. The amount of food
from the utilization table is subtracted
from the amount in the supply table.
The resulting food has "disappeared"
and is assumed to be consumed by the
population. Data on food composition
and edible portions of food are then
used to calculate the nutrients available
in the food supplies. Dietary comparisons
between countries are possible because
these data are all derived in this manner.
Differences between the U.S. and Italian
food supplies are therefore "real" and
not an artifact of different procedures.
Despite the limitation that data on the
food balance do not directly measure
dietary intake, these data can be used
to estimate the dietary patterns of the
Mediterranean region in the early 1960's
(8). Roughly 400 primary commodity
foods are included in the U.S. data set.
A more detailed discussion of the methods
for the estimates of U.S. nutrients per
capita is presented elsewhere (7).
FAO provided a spreadsheet of the
amounts of about 300 foods used by
the Italian population on a yearly basis
from 1961 to 1992 (4). In addition,
FAO supplied estimates of the Italian
population for those years. Food estimates
used in this study were divided
by the appropriate population estimates
to yield values on a kilogram per capita
per year basis. About 200 primary commodity
foods are included in the Italian
data set. A more detailed discussion of
the methods for the Italian nutrient per
capita is presented elsewhere (24 ).
Refuse and Edible-Portion Factors
We used refuse factors from USDA's
Nutrient Data Base for Standard Reference
Release No. 10 (18) to calculate
Family Economics and Nutrition Review
the amount of edible food in the food
supply. These factors were used to
adjust food amounts so that inedible
parts offoods (such as bones, rinds,
and seeds) are not included. When a
refuse factor for a food was not equal
to zero, we multiplied the food amount
by a value equal to one minus the refuse
factor. Averages of refuse factors were
calculated for some foods that were
reported only as a single value for
several food items.
Edible-portion factors for Italy were
provided by the INN. If a food had an
edible-portion factor with a value other
than 100 percent, we multiplied the per
capita amount of the food by its edibleportion
factor. When FAO reported
several foods as a total for a group of
foods, such as whole freshwater fish,
we calculated weighted averages of the
edible-portion factors within the group.
The method was based on the Italian
reference diet as described by Turrini,
Saba, and Lintas ( 14). When FAO values
of food per capita were grouped together
by the authors, the relative amount of
each food in the group was used to
develop a composite edible-portion
factor. When too little information
existed to calculate weighted edibleportion
factors, we calculated averages
for foods reported as groups.
Refuse factors are different from
inedible-portion factors, but usually
edible-portion factors are the refuse
values subtracted from 100 percent.
Refuse factors for the United States
and inedible-portion factors for Italy
were used to make the procedures for
both countries as similar as possible
and to account for food amounts that
typically are not available for human
consumption.
1999 Vol. 12 No. 1
Differences in the Food Per Capita
Data Sets
A method to estimate production from
home gardens has been developed for
estimating the nutrient content of the
U.S. food supply. This method incorporates
household consumption data from
USDA's Nationwide Food Consumption
Surveys ( 17) and the percentage of
households with vegetable gardens
from the National Gardening Association's
National Gardening Survey ( 1 ).
Data on vegetable consumption were
derived for the years in which USDA's
surveys were conducted and then interpolated
for the years between surveys
by using the percentage of households
with gardens.
Vegetables produced in small family
gardens are not included in the FAO's
statistics on food. Estimates have shown
that vegetables grown in family gardens
in Italy comprise almost 20 percent of
the total production of vegetables ( 3 ).
Thus, some nutrient per capita values
could be underestimated because these
sources of nutrients could not be included
in estimating the nutrient content
of the Italian food supply, particularly
those values for nutrients such as vitamin
A, ascorbic acid, and potassium
that are concentrated in vegetables.
For both countries the nutrients provided
by alcoholic beverages are excluded
from the estimates of nutrients per capita.
Vitamins and minerals added to the
food supply through drinking water
and supplements are also excluded in
each set of estimates of nutrients per
capita.
Nutrient Data Base Development
Sources of Data
Data on U.S. nutrient composition were
obtained from the Primary Nutrient
Data Set (PDS), which was developed
byARS's Nutrient Data Laboratory for
the 1994 Continuing Survey of Food
Intakes by Individuals ( 19). In addition,
food specialists in the Nutrient
Data Laboratory developed nutrient
profiles for unique items in the food
supply. Nutrient data provided on a per
100 gram basis were converted to a per
pound basis.
A nutrient database on a per kilogram
basis was developed based on the Italian
per capita food use estimates. Most of
the nutrient values were taken from
Tabelle di Composizione degli Alimenti
(2), maintained by the INN. Modifications
and additions were also made to
this nutrient database so that nutrient
profiles corresponded to food data.
In some cases, nutrient information
that corresponded to foods reported by
FAO did not exist in the INN database.
For these foods, we imputed nutrient
values from either USDA's 1991
Primary Nutrient Data Set ( 16), its
1976-1992 Agriculture Handbooks
(AH-8) ( 15 ), or its 1963 Agriculture
Handbook (22). The most recent source
of USDA data was used in all cases.
Differences in the Nutrient
Composition Data Sets
The values of nutrients per capita for
the United States include estimated
nutrient amounts added to the food
. supply through fortification and enrichment.
The nutrient amounts from fortification
and enrichment were based
on data from surveys of industry conducted
by the Bureau of Census for
USDA ( 5) and on advice about flour
29
30
In both countries,
the per capita per
year amounts of
most foods available
for consumption
increased.
enrichment from authorities in the
milling and baking industries ( 13 ).
Estimated nutrients include iron, thiamin,
riboflavin, and niacin added to flour
and cereal products; vitamin A added
to margarine, milk, and milk extenders;
and vitamin C added to fruit juices and
drinks, flavored beverages, dessert
powders, milk extenders, and cereals.
No comparable information was available
for Italy.
Another differe~ce between these two
data sets is the adjustment of the data
on nutrient composition to reflect technological
and marketing innovations
over time. In the United States, for
example, changes in animal husbandry
and closer fat-trimming practices by
the meat industry have lowered the fat
content of beef and pork since the late
1970's (6). To account for these changes,
nutrient values for beef and pork have
been updated since the mid-1970's.
Data were not available to determine
if such changes existed in the Italian
food supply; thus, we assumed that the
nutrient composition of foods used for
the Italian data set has not changed
over time. The nutrient composition of
most foods in the U.S. food supply did
not change between 1961 and 1992.
The major exceptions are the lower fat
content of beef and pork, the varying
fat content of poultry, and the higher
vitamin A content of deep-yellow
vegetables.
Results
Major Contributors Affecting
the Availability of Food
In both countries, the per capita per
year amounts of most foods available
for consumption increased (table 1).
Notable exceptions included less whole
milk and white potatoes in both countries,
less eggs and red meat in the United
States, and less grains in Italy. Over
the years, use of whole milk dropped
by 61 percent in the United States and
28 percent in Italy. Initially, milk use
in the United States was almost double
its use in Italy. Later, with the large
drop in the use of milk in the United
States, both countries had similar use.
Cow's milk was the predominant type
of milk in both countries. In Italy,
however, milk from other animals, such
as goat, ewe, and buffalo was more
common, particularly il_l cheesemaking.
Generally, the use of white potatoes in
both countries was similar and decreased
by 11 percent in the United States and
14 percent in Italy. While the use of
eggs in the United States surpassed
that of Italy over the series, their use
in the United States dropped by 23 percent
between 1961-65 and 1986-92.
Italian per capita values for grain
products, cheese, tomatoes, noncitrus
fruits, other vegetables, and oils were
all higher than U.S. values. For most
of the years, the use of Italian grains
was double that of the United States.
However, a decline in the use of grains
in Italy in 1986-92 resulted in Italian
use being less than double but still substantially
higher than U.S. use. Cheese
use in both countries doubled between
1961-65 and 1986-92. However, cheese
use was initially greater in Italy; thus,
the Italian increase was considerably
larger, causing the difference between
the two countries to become greater.
The use of vegetables and fruits was
substantially higher in Italy than it
was in the United States. For example,
Italians' use of tomatoes doubled, then
tripled, that of the Americans' use, and
the use of "other vegetables"4 in Italy
4Artichokes, asparagus, green beans, cabbage,
cucumbers, eggplants, lettuces, garlic, mushroom,
and cauliflower were counted in this group.
Family Economics and Nutrition Review
Table 1. Foods per capita per year in the U.S. and Italian food suppiieJ
1961-65 1966-70 1971-75 1976-80 1981-85 1986-92
Food group U.S. Italy u.s. Italy u.s. Italy u.s. Italy u.s. Italy u.s. Italy
Dairy
Whole milk
Lowfatmilk
Cheese
Eggs
Fats and oils
Fats
Oils
Meat, poultry, and fish
Red meat
Poultry
Fish
Grains
Sugars and sweeteners
Fruits
Citrus
Noncitrus
Vegetables
White potatoes
Tomatoes
Dark-green/deep-yellow
vegetables
Other vegetables
151.7
116.4
13.3
6.3
18.5
22.5
16.7
5.8
88.5
64.8
17.4
6.3
66.1
51.1
74.7
22.9
51.8
124.3
40.7
16.7
11.1
55.7
1 Values are the average for each year range.
1999 Vol. 12 No. 1
Kilograms
74.9 144.1 71.2 138.0 87.2 134.7
61.6 104.6 54.2 89.8 66.2 73.1
4.2 18.4 5.3 27.4 7.5 40.0
8.2 7.0 10.0 8.4 11.2 9.7
8.3 18.3 8.8 17.0 10.0 15.8
18.1 24.5 21.9 25.4 25.4 26.6
3.9 17.2 4.2 16.6 5.3 16.6
14.2 7.3 17.7 8.8 20.1 9.9
33.2 97.9 43.3 99.2 51.1 101.1
21.8 70.1 28.9 69.5 34.2 68.5
5.1 21.0 7.5 22.3 10.1 24.8
6.3 6.8 6.9 7.4 6.8 7.8
131.6 65.6 132.8 64.4 134.5 67.5
23.9 54.0 26.5 55.8 29.9 57.5
95.9 77.1 110.7 82.4 106.9 86.6
13.6 27.0 22.2 32.5 27.0 33.6
82.3 50.1 88.5 50.0 79.9 53.0
157.1 110.6 176.0 124.8 168.7 126.0
41.7 38.3 38.8 36.6 33.7 36.2
35.0 16.4 43.9 20.3 39.9 20.5
12.8 10.7 14.9 10.9 15.7 10.8
69.5 55.9 80.5 56.9 81.6 58.5
95.4 128.5 102.8 128.4 85.1
66.4 59.4 70.7 45.0 48.0
13.5 45.4 13.3 56.5 15.3
12.6 11.2 15.3 12.7 17.0
10.3 15.2 10.3 14.2 10.7
27.0 28.5 28.7 30.2 31.7
6.5 17.8 7.1 18.2 7.8
20.5 10.7 21.6 12.0 23.9
57.4 101.3 63.6 103.9 69.7
37.9 65.2 41.9 60.6 45.7
12.3 28.3 13.2 34.7 13.6
7.2 7.9 8.4 8.6 10.4
132.5 70.7 117.7 84.4 116.3
30.1 56.2 28.2 61.1 26.5
98.5 90.1 104.4 95.6 111.2
27.7 32.4 28.4 31.3 29.1
70.8 57.7 76.0 64.3 82.1
168.6 125.5 180.2 126.2 189.4
33.4 35.7 32.6 36.4 35.8
41.0 20.4 53.4 20.5 60.6
14.8 11.8 15.0 12.1 16.2
81.6 57.6 81.3 57.2 78.9
31
was greater throughout the entire series
and increased by 14 percent. Among
the vegetables in this group, artichokes,
cucumbers, eggplants, and cauliflower
were consumed in much larger quantities
in Italy than in the United States; the use
of sweet com, however, was common
in the United States but negligible in
Italy. In 1961-65, the use of dark-green
and deep-yellow vegetables was similar
in the two countries and increased. By
1986-92, Italian use of these vegetables
was 34 percent higher than their use in
the United States.
Originally, Italian use of noncitrus fruit
was almost 60 percent greater than its
use in the United States; by 1986-92 this
difference was reduced to 28 percent.
Additional analysis showed that the
most common noncitrus fruits in both
countries are apples, bananas, peaches,
pears, grapes, strawbenies, plums, cherries,
cantaloupes, and watermelons.
While figs and persimmons were more
common in Italy, pineapples were
more common in the United States.
The use of red meat, poultry, lowfat
milk, citrus fruit, fats, and sugars and
sweeteners was greater in the United
States than in Italy. While the use of
red meat in the United States was always
greater than that in Italy, the pattern of
use between the two countries differed.
In Italy, the use of red meat more than
doubled (21.8 to 45.7 kilograms per
capita per year) over the period; in
the United States, the use of red meat
increased through the 1960's and then
from 1966-70 to 1986-92, its use decreased
by 14 percent. Also, the use
of edible offals from animals such as
cows, pigs, horses, and chickens in
Italy was appreciable; in the United
States the use of offals was negligible
(data not shown). The use of fish in the
32
two countries was the same initially,
but by 1986-92, it was 21 percent
higher in Italy than in the United States.
The use of dairy foods and citrus fruits
for all years was higher in the United
States than in Italy. The use of lowfat
milk in the United States rose considerably,
with use in 1986-92 almost four
times its use in Italy. Although the use
of citrus fruit was higher in the United
States, a marked increase in its use
by Italians narrowed the difference
between the two countries-from 68
percent in 1961-65 to 8 percent in
1986-92.
The use of oil in Italy was 2 to 21/z times
greater than its use in the United States;
this difference narrowed in later years,
however. When we examined the oil
food group in more detail, we found
that olive oil was the predominant oil in
Italy in the earlier years (data not shown).
In 1961-65 the amount of olive oil
used per capita per year exceeded that
of all other types of oils, including oil
from maize, palm kernel, rapeseed,
sesame, soybean, and sunflower. By
1986-92, however, the sum of these
other oils was greater than the amount
of olive oil in the Italian food supply.
Use of oils, particularly soybean oil,
in the United States has practically
doubled.
Initially, the use of fats (butter, margarine,
shortening, and lard) by the United
States was more than four times that of
Italian use. Because of the subsequent
increase in the use of fats in Italy, the
United States was using no more than
twice as much as Italy used. Throughout
the series, ihe use of sweeteners in
the United States was twice their use
in Italy.
Macronutrients
In the United States and Italy, levels
of food energy increased by 17 and 18
percent, respectively (table 2). Despite
the similar percentage increases, the
United States consistently had higher
levels offood energy.
Even though food energy in both
countries increased consistently over
the years, the relative contributions
from carbohydrate, protein, and dietary
fat changed in Italy but remained rather
stable in the United States. From 1961-65
to 1986-92, the contribution of dietary
fat to total food energy increased from
28 to 37 percent in Italy and remained
stable at about 40 percent in the United
States (fig. 3). The contribution from
carbohydrate decreased from 61 to 49
percent in Italy but increased slightly
in the United States: from 48 to 50
percent. The protein contribution to
total energy for both countries remained
stable: 12 percent for the United States
and 13 percent for Italy.
Trends for the actual macronutrient
levels (amounts available in the food
supply) were more dramatic than their
relative contributions to energy indicate
(table 2). The most pronounced trend
was for dietary fat. Between 1961-65
and 1986-92, Italian fat levels increased
by 70 percent, quite a difference from
the increase in the U.S. fat levels: 13
percent. Although Italian fat levels
increased so dramatically, the United
States still had higher fat levels for all
years. However, the difference between
the two countries narrowed from 71
percent in 1961-65 to 14 percent in
1986-92.
There were several differences in fat
sources between the two countries
(fig. 4). Oils were the primary source
of dietary fat in Italy throughout the
Family Economics and Nutrition Review
Table 2. Food energy and macronutrients, vitamins, and minerals per capita per day in the U.S.
and Italian food supplies, selected year ranges
Food energy and macronutrients
Food energy Carbohydrate Protein Fat
Years U.S. Italy U.S. Italy u.s. Italy U.S. Italy
Kcal Grams Grams Grams
1961-65 3124 2849 374 437 91 89 140 82
1966-70 3259 3073 382 452 94 98 151 97
1971-75 3283 3258 386 459 94 104 151 112
1976-80 3337 3315 399 454 96 108 151 119
1981-85 3405 3274 403 421 98 109 156 128
1986-92 3641 3372 449 416 105 113 158 139
Vitamins
Vitamin A VitaminC Thiamin Riboflavin Niacin
Years u.s. Italy u.s. Italy u.s. Italy u.s. Italy u.s. Italy
mcgRE Milligrams Milligrams Milligrams Milligrams
1961-65 1264 902 91 177 1.8 1.7 2.2 1.5 20 21
1966-70 1407 1071 98 210 1.9 1.9 2.2 1.6 21 23
1971-75 1536 1170 108 212 2.1 1.9 2.3 1.8 23 24
1976-80 1533 1223 Ill 212 2.3 2.0 2.4 1.9 25 25
1981-85 1513 1341 ll2 219 2.3 2.0 2.4 1.9 26 25
1986-92 1509 1414 liS 225 2.6 2.0 2.5 1.9 28 26
Minerals
Calcium Phosphorus Iron Potassium
Years u.s. Italy U.S. Italy u.s. Italy U.S. Italy
Milligrams Milligrams Milligrams Milligrams
1961-65 902 718 1428 1482 14.2 14.9 3472 3328
1966-70 886 792 1449 1595 14.8 16.1 3465 3657
1971-75 873 868 1447 1684 17.0 16.8 3462 3691
1976-80 881 925 1471 1742 20.4 17.0 3465 3716
1981-85 888 985 1491 1753 17.5 17.0 3480 3846
1986-92 936 963 1608 1780 20.0 17.3 3657 3949
1999 Vol. 12 No. 1 33
34
Although the use
of citrus fruit was
higher in the United
States, a marked
increase in its use
by Italians narrowed
the difference between
the two countriesfrom
68 percent in
1961-65 to 8 percent
in 1986-92.
Figure 3. Macronutrient sources of food energy in the
U.S. and Italian food supplies, 1961-65 and 1986-92
100
80
60
40
20
0
.%Fat
0 %Protein
II % Ca!bohydrate
196Hl5 1986-92 1961-65 1986-92
United States
years; however, the types of oils shifted
from olive oil to other oils. In the
United States, while the contributions
of dietary fat from oil increased,
compared with use in Italy, ruargarine,
shortening, and lard were used in
greater quantities in the United States.
Thus, U.S. oils contributed less than
half the contributions from oils than
was the case in Italy. Since the early
1970's, the use of red meat in the
United States decreased. Despite the
decreasing use of red meat by the
United States since the early 1970's,
the contribution of fat from the meat,
poultry, and fish group between 1986-
92 was twice that from this group in
Italy.
The trends in carbohydrate levels were
very different between the two comtries.
Initially, Italy had a higher carbohydrate
Italy
level by 17 percent (437 vs. 374 grams
per capita per day); however, by the end
of the period, the carbohydrate levels
in the United States increased and surpassed
those for Italy by 8 percent (449
vs. 416 grams). Increased use of sugars
and sweeteners in both comtries and
an increased use of grains in Italy were
responsible for increased carbohydrate
levels. By the late 1970's, carbohydrate
levels began to drop in Italy because of
decreased use of grains.
The relative contributions of carbohydrate
from most foods remained fairly
constant for both countries (fig. 5).
During both periods, the grains group
was the primary source of carbohydrate
in Italy, contributing more than half of
the carbohydrate levels. In the earlier
period. the sugars and sweeteners group
and the grains group each provided
Family Economics and Nutrition Review
Figure 4. Sources of fat in the U.S. and Italian food supplies, 1961-65 and 1986-92
United States
1961-65
Italy
1961-65
Other fats
poultry,
and fish
Other
fats
1986-92 1986-92
37 percent of the carbohydrate in the
United States (fig. 5). By 1986-92, the
major source of carbohydrate in the
United States was the grains group,
followed by the sugars and sweeteners.
Protein levels, similar in the earlier
years, increased for both countries,
with a 15- and 27-percentincrease,
respectively, in the United States and
Italy (table 2). In the United States, the
red meat group was the leading source
of protein, providing between 26 and
23 percent (data not shown). In Italy
the grains group was the largest source
of protein for the entire period even
though grain contribution .dropped.l4
percent. ln Italy the relative contribution
from the red meat group increased
1999 Vol. 12 No. 1
during this period, while in both countries
the protein contribution from poultry
increased.
Vitamins
In both countries, vitamin levels have
generally increased (table 2). The
United States had higher levels for
vitamin A, thiamin (particularly in
later years), and riboflavin; whereas,
Italy had much higher ascorbic acid levels.
Niacin levels in both countries were
initially similar; however, in the late
1970' s, the niacin levels in the United
States surpassed those in Italy.
Levels of total vitamin A, which includes
both retinol and beta carotene, increased
substantially (57 percent) in the Italian
Meat, poultry,
and fish
food supply, narrowing the U.S. lead:
from a 40- to a 6-percent difference
in the levels between the countries in
1961-65 and 1986-92, respectively.
The meat group, particularly organ
meats, and dark-green and deep-yellow
vegetables were leading sources of
vitamin A for both countries (fig. 6).
From 1961-65 to 1986-92, the vitamin
A contribution from the vegetable group
was about two-fifths (45 percent) and
that from the meat, poultry, and fish
group increased from one-fifth to onefourth
in the Italian food supply. At the
same time in the United States, vitamin
A contributions from the vegetable
group increased from about one-fifth
to one-third (23 to 34 percent), and meat
contributions dropped from one-third
35
Figure 5. Sources of carbohydrate in the U.S. and Italian food supplies, 1961-65 and 1986-92
United States Italy
1961-65 1961-65
Sugars and
sweeteners
Vegetables
Grains
Other
=------1 Dairy
2%
Sugars and sweeteners
1986-92 1986-92
to about one-fifth (33 to 22 percent).
The greater vitamin A contribution
from the vegetable group in the United
States was not from increased use but
rather from the introduction in the
mid-1960's of varieties of deep-yellow
vegetables with more carotene than
was true for earlier varieties. Another
difference in contributions of vitamin
A from the vegetable group was that in
Italy, tomatoes (due to a sizable use
over the years) were important contributors
of vitamin A, unlike the trend
in the United States. In the United
States, because of the use of vitamin Afortified
margarine, the vitamin A
contributions from fats and oils were
appreciably higher, compared with
36
contributions of vitamin A from fats
and oils in Italy.
Throughout the series, ascorbic acid
levels in Italy were almost double the
levels in the United States. In both
countries, ascorbic acid levels increased:
from 91 to 115 mg in the United States
and 177 to 225 mg in Italy. The relative
contribution from the various food
groups was rather stable over the years
(data not shown). Contributions from
fruits and vegetables comprised 90
percent or more of the levels of total
ascorbic acid. In the later years of the
series, fruit and vegetable contributions
in the United States provided similar
levels; in Italy, vegetables provided the
majority of vitamin C.
3%
Over the 30-year period, thiamin and
riboflavin levels were higher in the
United States than they were in Italy.
In the United States, thiamin levels
increased dramatically, by 44 percent;
riboflavin levels increased by only
14 percent. Riboflavin levels in the
United States rose from 2.2 to 2.5 mg
(14-percent increase) per capita per day
over the series; levels in Italy rose from
1.5 to 1.9 mg (27-percent increase).
Also, niacin levels in the United States
were higher than the levels in Italy
were at the end of the series. Higher
levels of these nutrients in the United
States were, in part, due to an increase
in the use of grains, but more substantially,
these levels were due to Federal
enrichment of grain products. With a
Family Economics and Nutrition Review
Figure 6. Sources of vitamin A in the U.S. and Italian food supplies, 1961-65 and 1986-92
United States
1961-65
Italy
1961-65
Fruit
Other
vegetables
Dark-green,
deep-yellow
vegetables
1986-92
decrease in the use of red meat in the
United States, its contributions to these
three vitamins dropped from 23 to 17
percent for thiamin, 17 to 14 percent
for riboflavin, and 29 to 20 percent for
niacin (data not shown). A reverse
trend occurred in Italy: thiamin contributions
from the red meat group more
than doubled, primarily reflecting an
increase in pork use. Also, Italian riboflavin
contributions from the meat,
poultry, and fish group increased from
10 to 16 percent. Reflecting the drop
in grain use in Italy, contributions from
this group for thiamin declined from
46 to 36 percent, for riboflavin from
21 to 15 percent, and for niacin from
37 to 27 percent (data not shown).
1999 Vol. 12 No. 1
Other
vegetables
Dark-green,
deep-yellow
vegetables
1986-92
In both countries, the riboflavin contribution
from the milk group dedined
because use dropped. The relative
importance of the vegetable group to
the supply of riboflavin was different
between the two countries throughout
the series: the Italian vegetable group
provided about 20 percent of the riboflavin;
whereas, the U.S. vegetable
group provided about 7 percent.
Minerals
From 1961-65 to 1986-92, the levels
of calcium, phosphorus, iron, and
potassium in the food supplies of both
countries generally increased (table 2).
Italian calcium levels surpassed those
of the United States during the late
1970's. From 1961-65 to 1966-70,
Italian potassium levels increased by
10 percent and quickly outpaced the
rather stable U.S.levels. The primary
source5 of potassium in both food
supplies was the vegetable group.
The other sources of potassium differed
in their importance between the two
food supplies. Other major Italian food
sources were grain products and fruits.
Higher levels of potassium in Italy were
mainly due to increased contributions
from the meat, poultry, and fish group.
Contributions from Italian dairy products
remained stable at 9 percent but were
minor compared with U.S. dairy product
contributions, which provided about
one-fifth of the total potassium
throughout the years.
5Data on sources of potassium are not shown.
37
Figure 7. Sources of calcium in the U.S. and Italian food supplies, 1961-65 and 1986-92
United States Italy
1961-65 1961-65
Other
Other dairy , Other dairy
2%
1986-92 1986-92
Iron levels were similar for both countries
in the early years, but by the mid-1970's,
U.S. levels were higher (20.4 vs. 17 mg).
Italy had higher phosphorus levels for
the entire period: 1,482 to 1,780 mg
versus 1,428 to 1,608 mg for the
United States.
Calcium levels in the Italian food
supply increased by 34 percent, while
U.S. levels fluctuated slightly but by
1986-92 were similar to the Italian
level. Throughout the period, dairy
products were the primary calcium
source in both countries; however,
over the years, dairy products provided
50 to 60 percent of the calcium in the
Italian food supply and 74 to 77 percent
of the calcium in the U.S. food
38
supply (fig. 7). In both countries, the
contributions from cheeses and lowfat
milks increased; the contributions from
whole milks decreased. In the United
States, the contribution of cheeses to
calcium levels more than doubled, lowfat
milk quadrupled, and whole milks
dropped by more than half.
In the United States, calcium contributions
from the vegetable group wer::!
small (6 percent), compared with contributions
from this group in the Italian
food supply: around one-fifth (20 to
23 percent) of the total calcium in the
Italian food supply, the result throughout
the series of the ample use of ~any
vegetables-particularly tomatoes and
dried onions.
U.S. and Italian food sources of phosphorus
differed (data not shown). In
Italy, the primary source of phosphorus
was the grain group; in the United States,
the dairy group was the primary source.
However, the share of phosphorus
provided by grain products to the U.S.
food supply increased, while the share
in the Italian food supply dropped but
continued to be the major source. The
dairy group (especially cheese) became
a more important source of phosphorus
in the Italian food supply over the years,
increasing from 18 to 22 percent. Also,
the contributions from the meat, poultry,
and fish group increased in the Italian
food supply; in the United States, this
group's contributions remained stable.
Phosphorus contributions from vegetables
Family Economics and Nutrition Review
Figure 8. Sources of iron in the U.S. and Italian food supplies, 1961-65 and 1986-92
Legumes, nuts,
and soy
United States
1961-65
Vegetables
Legumes, nuts,
and soy
Italy
1961-65
Meat, poultry,
and fish
1986-92 1986-92
in the Italian food supply were about
two times greater than those from
vegetables in the U.S. food supply. The
contributions from vegetables were
relatively stable in both countries.
Per capita per day levels of iron in the
two countries increased over the years;
however, U.S. iron levels became
noticeably higher in the mid-1970's
because of enrichment and fortification
practices. Grain products were the
predominant source of iron for both
countries (fig. 8). The relative contributions
from grfiins decreased in the Italian
food supply (37 to 28 percent), while
those from the meat, poultry, and fish
group (14 to 24 percent), particularly
pork, increased. In the United States,
1999 Vol. 12 No. 1
the trend reversed-grains c0ntributed
more (35 to 49 percent) and meat,
poultry, and fish less (23 to 49 percent).
For Italy, the vegetable group remained
a stable and important source of iron
to the food supply (24 percent). In the
United States, this group contributed
a moderate but decreasing amount of
iron (15 to 11 percent). In both countries,
the legumes, nuts, and soy products
provided modest amounts of iron
throughout the series.
Conclusions
Discussion
Interest in the Mediterranean diet
started with the work of Ancel Keys.
In 1952, he and several colleagues
undertook dietary and other coronaryrisk
studies in seven countries. After
examining the results from these different
countries, he was one of the first to link
high-fat diets to higher concentrations
of blood cholesterol and a subsequent
increased risk of heart disease. To help
individuals reduce their risks for coronary
heart disease, he wrote a cookbook
in which he summarized his findings
and provided advice for a healthy lifestyle.
Nestle ( 11) surmised that the
Mediterranean diet of the 1960's was
the prototype for current dietary guidance
policy in the United States because
the Dietary Guidelines for Americans
(21) reflect the advice Keys outlined in
his cookbook. This observation prompted
us to compare the Mediterranean diet
39
to the U.S. diet in order to better quantify
the characteristics of the Mediterranean
diet.
Keys attributed the beneficial effects
of the Mediterranean diet to the amount
and type of fat consumed; however, in
this study there were differences in the
availability of other foods and nutrients.
For example, vitamin C, calcium, phosphorus,
and potassium levels were higher
in Italy than in the United States. Thus
it is difficult to ascertain if only one
component, such as fat, is the only
causative factor in the etiology of
chronic diseases.
The successful implementation of
dietary recommendations requires
consumer access to affordable, healthpromoting
foods. From 1961-65 to
1986-92, substantial changes in the
quantity and quality of foods in both
countries resulted in different levels
of nutrient availability. These different
levels consequently caused the healthpromoting
attributes of these diets to
be altered.
This study shows an increase in availability
of fruits and grains in the United
States and a shift to lower fat dairy and
leaner meat products. However, along
with these healthful trends, the U.S.
food supply contains less dairy foods,
more sugar and sweeteners, and more
fat and oils in 1986-92 than in 1961-65.
These trends resulted in higher levels
of most vitamins and minerals; however,
the 1986-92levels of calcium (too low),6
total fat (too high), and calories (too
high) may be a concern in terms of
dietary guidance. As with the United
States, the Italian food supply diet had
6Despite higher levels of calcium in 1986-92,
these levels are below the calcium recommendations
for many subgroups of the population.
40
available for consumption more fruits
and fats and oils in 1989-92 than in
1961-65. A healthful trend in Italy
(not seen in the United States) was the
increase in dairy products and vegetables
available for consumption.
Trends that deviate from dietary guidance
recommendation were the decreased
use of grains and increased use of red
meats and sugars and sweeteners in
Italy. Determining the overall healthfulness
of these two food supplies is difficult
because the consumption of some
foods came closer to dietary recommendations,
and others deviated from
dietary recommendations. Dietary
quality is difficult to measure. The
food supply of both countries must be
able to provide healthful food choices.
For the U.S. population to consume a
diet typical of the Mediterranean area
in the 1960's, the availability of several
food groups would need to change.
When comparing the foods ofltaly in
1961-65 to those in the United States
in 1986-92, we found that Italy had
less milk, cheese, eggs, fats, meat,
chicken, fish, sugars, sweeteners, and
citrus fruit available in 1961-65. Italy
had more oils, grains, noncitrus fruit
white potatoes, tomatoes, dark-green/
deep-yellow and other vegetables available
in 1961-65. As O'Brien ( 12) has
noted, this would have significant
implications for the agricultural sector
in the United States. The current state
of the U.S. food supply could not accommodate
the estimated food needed
for the U.S. population to adhere to a
Mediterranean diet. However, whereas
using the Mediterranean diet as a dietary
guidance model in the United States
might not be feasible at this time, the
food industry has shown the capacity
to adopt over time to changes in
consumer demands and changing
public policy.
Data Limitations
When food supply data are used to
examine dietary patterns, concerns
always arise regarding differences
noted between food supply data and
dietary intake data. Food supply data
measure food and nutrient availability
as national totals; whereas, dietary survey
data (such as USDA's <:;ontinuing
Survey of Food Intakes by Individuals)
provide data on food and nutrient intakes
reported by individuals and households.
Both types of data have strengths and
limitations that affect their ability to
measure food consumption and their
usefulness in dietary assessment. Estimates
of the food supply reflect the
amount of food available before it
moves through marketing channels,
not the amount actually consumed.
Thus food supply data typically
overestimate food and nutrient availability
and are better indicators of trends
in consumption over time rather than
actual amounts ingested. On the other
hand, the quality of the dietary or food
intake survey depends on the accuracy
and completeness of the individual's
recall. Underreporting of the total diet
or different food groups by respondents
is common in these surveys, and actual
food intakes may be underrepresented.
Another concern: fortification and
enrichment estimates. USDA and Italian
nutrient databases do not routinely
identify levels of added nutrients.
Fortification data in the U.S. food
supply have not been updated since
1970, except for the percentage of
flour enriched. Since 1970, enormous
changes in fortification practices by the
food industry have occurred, and both
the range of fortified foods and the
number of added nutrients expanded.
Family Economics and Nutrition Review
An updated version of USDA's food
composition database, designed to
include nutrients added to foods commercially
through enrichment and
fortification, is needed to generate
more accurate estimates of nutrients
in the food supply. Based on personal
communications with Italian authorities,
we found that enrichment and fortification
are not commonly practiced in
Italy. Therefore, the higher U.S. levels
for thiamin, riboflavin, and niacin are
most likely real and not from a difference
in methods.
The ability of estimates of the food
supply to reflect accurately the contribution
of fat from the meat group is
another concern. The contribution of
red meat in the U.S. food supply has
been completely revised (6), thus these
estimates reflect more closely the trends
in fat contributed by meat. The composition
of red meat in Italy has also
undergone a shift to more leaner types,
and this is probably not reflected in the
food composition values used for Italy.
Thus the contribution of fat from meat
is probably overestimated for Italy.
Because the Italian diet of the 1960's
is no longer common, using it as a
model is difficult. Many individuals
would assume that the current Mediterranean
diet is the model; as illustrated
by this study, that assumption would
be misleading. The effects on the health
of those living in the Mediterranean
area caused by changes in their diets
require further research. The protective
effect of the Mediterranean diet in terms
of coronary heart disease may no longer
exist, and perhaps the health of those
currently living in the Mediterranean
region would benefit by their returning
to the diets of their grandparents.
1999 Vol. 12 No. 1
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Family Economics and Nutrition Review
Rodolfo M. Nayga, Jr.
Texas A&M University
Debra B. Reed
Texas A&M University
1999 Vol. 12 No. 1
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