Documentation
ERS provides data on food and nutrient intake by food
source:
- Three tables provide estimates of food consumption in 2003-04
relative to recommendations from the 2005 Dietary Guidelines for Americans.
- Two tables provide estimates of nutrient intake in 2005-08 by
food source.
About Our Estimates
The National Health and Nutrition Examination Survey (NHANES)
measures foods actually eaten by individuals. Since 2003, NHANES
has recorded food intake over 2 nonconsecutive days using 24-hour
dietary recalls to obtain information about what people eat. Survey
respondents also reported where food was purchased and where it was
eaten.
NHANES collects demographic information, such as household
income, race and ethnicity, age, and sex, along with a variety of
health data, through household interviews and medical examinations
conducted in-person at mobile examination centers. This information
makes the data particularly valuable for linking diet and eating
habits to health outcomes such as obesity, diabetes, and
hypertension. The NHANES data provide background information useful
in policy formation, regulation, program planning and evaluation as
well as education and research.
Food consumption estimates
Food consumption data from NHANES were combined with USDA's
MyPyramid Equivalents Database (MPED) to estimate food consumption
by food groups as specified in the 2005 Dietary Guidelines for
Americans. The MPED database translates food quantities
reported in NHANES into MyPyramid equivalents as specified in the
Dietary Guidelines for Americans. For example, a
respondent in NHANES may report having eaten a specific amount of
apple pie; such data are then translated into cups of fruit, ounces
of grain, teaspoons of solid fat and/or teaspoons of added sugar.
While NHANES data are available through 2008, the most recent MPED
data are for 2003-04. Thus, ERS compares food consumption in
2003-04 to the recommendations put forth in the 2005 Dietary
Guidelines for Americans.
Data on where food is obtained are used to divide food into 2
categories-at-home and away-from-home food.
- Food at home is generally obtained at a retail store such as a
supermarket, grocery store, or convenience store.
- Food away from home is generally purchased from foodservice
establishments such as full-service restaurants with waitstaff,
fast food restaurants with limited menus and no waitstaff, and
carryout places. Food away from home can also be obtained from
school cafeterias, day care centers, and summer camps for children
age 2-19 as well as from other community food programs.
Food consumption in terms of the Dietary Guidelines for
Americans' groups is reported for all sources and the total
U.S. population, as well as by food source, children age 2-19, and
adults age 20 and older.
In food consumption table 1, calorie intake in 2003-04 is also
reported. By comparing food consumption data with calorie intake
data, food consumption can be expressed in terms of density-the
amount of food for each 1,000 calories contained in an American
diet. This density measurement is used in USDA's calculation of the
Healthy Eating Index. By comparing food consumption density
with the benchmark density (a ratio of the recommended consumption
amount to calorie intake as specified in the Dietary Guidelines
for Americans), insight can be gained about shortfalls in
American diets relative to the dietary guidelines. Comparing food
consumption density by food source yields a better understanding of
the source of American dietary shortfalls. Food consumption density
for children and adults as well as density by food source are
reported in food consumption table 2. The benchmark food density is
presented in food consumption table 3.
Nutrient intake estimates
Studies have shown that Americans tend to over-consume fats,
sodium, and cholesterol but under-consume calcium, fiber, and
iron. Using USDA's nutrient database, food consumption data in
NHANES were converted to nutrient consumption data. Average (mean)
intakes of these nutrients for the total U.S. population, children
age 2-19, and adults age 20 and older are reported by food source
in nutrient table 1. Mean calorie intakes are also reported in
table 1. Nutrient intake can be expressed in terms of density
by the ratio of nutrient intake to calorie intake; the result can
then be compared with the dietary recommendations.
Recommended nutrient intakes (macronutrients and minerals) which
vary by age and gender are provided from two sources. The 2010
Dietary Guidelines for Americans has a
complete list of recommended nutrient intakes. Due to variations in
daily nutrient intake, two-day intake data are used to estimate
usual intakes; these can then be compared with the dietary
recommendations. The Agricultural Research Service, USDA also reports usual nutrient intake data by demographic
characteristics, but not by food source.
Mean nutrient intakes are reported by food source in nutrient
table 1 and by nutrient density in table 2, providing insight about
sources of over- and under-consumption of various nutrients. For
example, foods rich in calcium are essential for children's
development. According to nutrient table 2, the mean calcium intake
for children age 2-19 is 511 milligrams per 1,000 calories. Calcium
intake by source shows that, for each 1,000 calories, children
consume 542 milligrams of calcium at home, lower than the amount
consumed at school (650 milligrams) but higher than the amount
consumed at restaurants (364 milligrams) and fast food places (381
milligrams). The increased popularity of eating away from home-at
restaurants and fast food places-is associated with a deficiency in
calcium intake.