The U.S. Department of Agriculture's Nationwide Food Consumption Survey is the largest of several food surveys conducted by the federal government. Here is a close-up look at the major nutrition surveys the government conducts:
The USDA's Nationwide Food Consumption Survey (NFCS), conducted every 10 years, focuses on both individual intakes, with three 24-hour dietary recalls, and household consumption, which tracks all the food a family brings into the home for a week. The next survey, planned for 1987-88, will question 15,000 to 17,000 individuals in 6,000 "basic" households and an additional 10,000 to 11,000 individuals in 3,600 low-income households.
The survey will be fully computerized with interviewers taking portable computers into the homes of the families to enter food intake and answers to demographic questions about income, age and education. Total cost of the survey is expected to be $6 million.
In the USDA's 1977 survey, respondents got $1 a day for filling out their food diaries. They also received a set of measuring cups and spoons to help them figure out how much they were eating.
The 1987 survey will track 28 nutrients in the American diet -- including sodium, cholesterol, fiber, folacin, and saturated and unsaturated fat -- up from 14 in 1977. A greatly expanded nutrient data bank will enable USDA staffers to immediately break down common recipes -- such as macaroni and cheese -- into ingredients and then into a nutrient profile. Nutrient data on many fast foods and brand-name foods also will be available.
The Department of Health and Human Services' National Health and Nutrition Examination Survey (HANES) has been conducted every few years since 1971, with the third survey scheduled to begin in 1988. This survey results in a complete health profile of the American public, coupling 24-hour dietary intake information with medical history, a physician's examination, a dental exam, body measurements, and biochemical tests that measure key vitamins and minerals in the blood.
The survey also questions respondents about the frequency with which they eat certain foods, asking them how many times per week over the last three months they have consumed such foods as skim milk, fish or eggs. This helps researchers look at what certain groups of people, such as those with abnormal blood pressure or high cholesterol, usually eat.
According to Robert Murphy, director of the division of health examination statistics in HHS' National Center for Health Statistics, tentative plans for the HANES III survey call for a six-year survey, comprised of three two-year cycles, examining 20,000 people every two years. Although this would be more costly than past HANES surveys, Murphy says it would help experts to spot trends about the nutritional status of key populations in the U.S.
The medical field teams that conduct the examinations live a nomadic life, traveling in mobile trailers that move from one community to another across the nation.
HHS has just completed a two-year Hispanic Health and Nutrition Examination Survey of 15,000 Americans of Mexican, Puerto Rican and Cuban ancestry residing in the southwestern United States, the New York City area and Dade County, Fla. Initial results are expected to be released this fall.
The USDA's Continuing Survey of Food Intakes by Individuals is the department's response to calls for a continuous survey, though it is funded only for two years at approximately $2 million per year. One hundred interviewers contacted 2,400 households in a two-month period, which began in April, to obtain the dietary intakes of women in those households aged 19 to 50 and their children who are between 1 and 5 years of age.
Approximately every two months thereafter, the respondents will be contacted again -- by telephone if they have one -- for 24-hour dietary recalls, so that by the end of the year, the USDA will have data on six 24-hour dietary recalls for every person in the survey. This information will help to more accurately profile a person's usual diet. The survey will include a representative sample of low-income households. USDA staffers hope to be able to sample men between the ages of 19 and 50 next year while continuing the sample of the "core" group of women and children.
The Food and Drug Administration's Total Diet Survey is an annual program that analyzes some 200 foods purchased in selected grocery stores across the United States to assess dietary exposure to minerals, toxic elements, radionuclides, industrial chemicals and pesticides. Selection of the foods is based on actual consumption data obtained from NFCS and HANES.