Nutrient Availability Documentation
Using ERS data on the amount of food available for consumption and information on the nutrient composition of foods from USDA's Agricultural Research Service (ARS), USDA's Center for Nutrition Policy and Promotion (CNPP) calculates the nutrient content of the U.S. food supply, or nutrient availability. This historical data series estimates the amounts per capita per day of food energy (calories) and 27 nutrients and dietary components (for example, protein, carbohydrates, fats, vitamins, and minerals) in the U.S. food supply. The data available here summarize the nutrients and other food components available per capita per day in the U.S. food supply between 1970 and 2010, and the nutrients contributed by the major food groups, per capita per day for 1970 and 2010. The entire historical series, including an interactive version of the data, is available on the CNPP website (see Nutrient Content of the US Food Supply).
Coverage of the Data
Per capita estimates are made for food energy and energy-yielding nutrients: protein, carbohydrates, and fat (total, saturated, monounsaturated, and polyunsaturated), cholesterol, dietary fiber, 10 vitamins, and 9 minerals. Estimates of percentage contributions of nutrients by major food groups and quantities of nutrients available for consumption are provided for 1970 and 2010 for each of the nutrients and dietary components included in this series.
Nutrient Availability Coverage in ERS Tables
Nutrients and other food components include: food energy, carbohydrates, protein, fat (total, saturated, monounsaturated, and polyunsaturated), cholesterol, and dietary fiber; vitamins (vitamin A, carotene, vitamin E, vitamin C, thiamin, riboflavin, niacin, vitamin B6 , folate, and vitamin B12); minerals (calcium, phosphorus, magnesium, iron, zinc, copper, potassium, selenium, and sodium).
Nutrients contributed from major food groups, include: meat, poultry, and fish; dairy products; eggs; fats and oils; sugars and sweeteners; fruit (citrus and noncitrus); legumes, nuts, and soy; grain products; vegetables (white potatoes, dark green, deep yellow, and other vegetables; and miscellaneous.
Constructing the Data
The food composition data used to estimate nutrients available in the U.S. food supply were obtained from the Primary Nutrient Data Set (PDS), which contains information about foods and their nutrient profiles, and from USDA's Nutrient Database for Standard References developed by ARS's Nutrient Data Laboratory (NDL).
To calculate nutrient estimates, ERS's annual per capita availability estimate for a commodity is multiplied by the amount of food energy and each of 27 nutrients and dietary components found in the edible portion of the food. Results for each nutrient from all foods are totaled and converted to the amount per capita per day. Nutrients added to certain commodities commercially through fortification and enrichment are also included in the nutrient content of the food supply. Since food availability data represent the disappearance of food into the marketing system, per capita availability and nutrient estimates typically overstate the amount of food and nutrients people actually ingest.
Nutrient values exclude nutrients from the inedible parts of foods, such as bones, rinds, and seeds, but include nutrients from edible parts of food that are not always eaten, such as separable fat on meat.
Limitations of the Data
Nutrient estimates are currently based on the ERS Food Availability Data System and not the Loss-Adjusted Food Availability Data System; thus, they represent nutrients and foods available for consumption and not actual nutrient intakes by individuals. Nutrient levels of the food supply should exceed recommended allowances because these values do not account for further losses from trimming, cooking, plate waste, and spoilage. Another limitation is that per capita values are averages for the U.S. population, although food is not equally distributed among the population.
Usefulness of the Data
Nutrient estimates reflect market conditions, technological developments, up-to-date food composition values, and nutrients added commercially through enrichment and fortification. Nutrient levels and nutrient contributions from major food groups to the U.S. food supply are used to examine historical trends and evaluate changes in the average American diet over time.
Estimates of nutrients available per capita in the U.S. food supply have historically played a key role in nutrition monitoring activities. These estimates are needed to monitor the food supply's potential 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 over time. These estimates provide unique and essential information about the amount of food and nutrients available for human consumption in the United States. Food supply nutrients are closely linked to food and nutrition assistance policy, Federal dietary guidance, nutritional requirement guidelines, nutrition education, fortification policy, and food marketing strategies.