Frequently Asked Questions
Frequently Asked Questions and
Answers about the U.S. Food Supply
is the U.S. Food Supply?
Role does the U.S. Food Supply have in Nutrition Monitoring?
does the U.S. Food Supply Relate to Federal Dietary
the U.S. Food Supply Reflect Changes made by the Food
the U.S. Food Supply Account for Technical Changes and Marketing
Practices changes over time?
U.S. Food Supply Nutrient Estimates Comparable to Nutrient
Estimates on FAO Food Balance Sheets?
are U.S. Food Supply Nutrient Estimates Calculated?
is the Source of Food Composition Data used in the U.S. Food
are the Limitations of the U.S. Food Supply?
does the U.S. Food Supply Series Differ from the USDA Dietary
- What is the U.S. Food Supply?
A. The U.S. Food Supply is a historical data series, beginning with
1909, on the amounts of nutrients per capita per day in food available
for consumption. Per capita estimates are made for energy and the energy--yielding
nutrients-protein, carbohydrate, and fat--as well as for total saturated,
monounsaturated, and polyunsaturated fatty acids, cholesterol, dietary
fiber, 10 vitamins, and 9 minerals.
- What Role does the U.S. Food Supply have
in Nutrition Monitoring?
A. Food supply per capita nutrient estimates play a key role in nutrient
monitoring activities. They are needed to monitor the potential of the
food supply to meet the nutritional needs of the U.S. population, as
well as to examine historical trends, and to evaluate changes in the
American diet. These estimates provide unique and essential information
on the amount of food and nutrients available for human consumption
in the United States. The U.S. food supply series is one of the five
major components of the National Nutrition Monitoring and Related Research
Program (NNMRRP) established by the National Nutrition and Related Research
act of 1990.
- How does the U.S. Food Supply Relate to Federal
A. In support of Federal dietary guidance food supply nutrient data
are important to agriculture and nutrition policymakers for translating
nutrient goals for Americans into goals for food production and supply
levels. Over the years, a nutritionally adequate food supply has been
linked to providing sufficient energy, macronutrients, and micronutrients
to meet the nutritional needs of the U.S. population. To ensure that
sufficient nutrients are available to the whole population, the nutrient
levels in the food supply need to exceed recommended allowances because
the estimates reflect the amount available before losses from trimming,
cooking, plate waste, and spoilage. For more information consult our
Related publications list.
- Does the U.S. Food Supply Reflect Changes made
by the Food Industry?
A. Food supply nutrient estimates reflect the food industry's response
to Federal dietary guidance and consumer demand for lower fat and leaner
products. Most recently, many of the production techniques and marketing
changes made by the food industry have been responsive to and reflective
of dietary recommendations for total fat, saturated fat and cholesterol.
- Does the U.S. Food Supply Account for Technical
Changes and Marketing Practices changes over time?
A. Food supply nutrient data are useful in evaluating the effects of
technological alterations and marketing changes on the food supply over
time. Technological changes and improved marketing practices produce
an even greater number and variety of foods, respond to consumer demand
for convenient and healthful foods, and generally enhance the health
benefits associated with the food supply. Alteration of the food supply
may consist of the addition of nutrients or the removing of nutrients
or dietary component. The addition of nutrients to foods through enrichment
and fortification has been an effective way to maintain and improve
the overall nutritional quality of the U.S. food supply.
- Are U.S. Food Supply Nutrient Estimates Comparable
to Nutrient Estimates on FAO Food Balance Sheets?
A. The U.S. food supply series continues to be the major source of U.S.
dietary information with which international comparisons can be made.
The methodologies used to estimate foods and nutrients available for
consumption in the United States are similar to those used by the Food
and Agriculture Organization (FAO) of the United Nations for other countries.
Both methodologies are based on the concept of food balance sheets,
which include data on the supply and utilization of food. Thus, these
data can be used to compare the U.S. diet with diets of other countries.
- How are U.S. Food Supply Nutrient Estimates
A. The nutrient content of the food supply is calculated using data
on the amount of food available for consumption from USDA's Economic
Research Service (ERS) and information on the nutrient composition of
foods from USDA's Agriculture Research Service (ARS). Estimates of per
capita consumption for each commodity (in pounds per year) are multiplied
by the amount of food energy and each of the nutrients and dietary components
in the edible portion of the food. Results for each nutrient from all
foods are totaled and converted to amount per capita per day.
- What is the Source of Food Composition Data
used in the U.S. Food Supply?
A. The food composition data used to estimate the nutrients available
in the Food Supply are obtained from USDA's ARS Nutrient Data Laboratory
(NDL) and include: the Primary Nutrient Data Set (PDS), which contains
approximately 3,000 foods and their nutrient profiles; the most current
USDA National Nutrient Database for Standard Reference; and food specialists
who develop nutrient profiles for food supply unique items. Food composition
values are based primarily on laboratory analysis. If laboratory values
are not available, values are imputed from data for other forms of the
same food or from data for similar foods.
- What are the Limitations of the U.S. Food Supply
A. The food supply is usually a residual that makes the supply-utilization
commodity table balance. The disappearance method of calculation relegates
to the food supply all residual uses for which data are not available,
such as miscellaneous nonfood uses, stock changes at retail and consumer
levels, and sampling and measurement errors in the estimation of other
components of the balance sheet. For example, an increasing proportion
of the total turkey supply (especially backs, necks and giblets) goes
into pet foods. But it is currently included in food disappearance.
Thus, this report probably over states turkey consumption.
Food disappearance is often used as a proxy to estimate human consumption.
Used in this manner, the food supply usually provides an upper bound
on the amount of food available for consumption. Food disappearance
estimates can overstate actual consumption because they include spoilage
and waste accumulated through the marking system and in the home.
The food disappearance series is becoming a less reliable indicator
of change over time in ingestion of food fats and oils. While food disappearance
reflects trends in fats and oils sold for human food, it probably does
not accurately measure food eaten because the waste portion of fats
and oils has increased during the past two decades with the growth in
away from-home eating places, especially fast-food places. Food services
establishments that deep-fry foods can generate significant amounts
of waste grease, referred to as restaurant grease.
U.S. Food Supply data do not reflect good data for final processed products,
such as salad dressing or bakery products.
- How does the U.S. Food Supply Series Differ
from USDA's Dietary Survey?
A. Food supply data measure food and nutrient availability as national
totals, whereas dietary survey data (such as USDA's Continuing Survey
of Food Intakes by Individuals) provide data on food and nutrient intakes
reported by individuals and households. Also, dietary food intake survey
record food intake data over specific time period and combine it with
demographic information. These data are used to assess food consumption
behavior and the nutritional content of diets for policy implications
relating to food production and marketing, food safety, food assistance,
and nutrition education. Food supply data best serve the purpose of
trend analysis of food and nutrient consumption over time.