What We Eat in America (WWEIA) is the dietary intake interview component of NHANES. WWEIA is conducted as a partnership between the Department of Agriculture (USDA) and the Department of Health and Human Services (DHHS). DHHS is responsible for the sample design and data collection, and USDA is responsible for the survey’s dietary data collection methodology, maintenance of the databases used to code and process the data, and data review and processing. USDA also funds the collection and processing of Day 2 dietary intake data, which are used to develop variance estimates and calculate usual nutrient intakes.
The 2001-04 NHANES included the collection of 1 day of dietary data for all respondents through in-person 24 hour recalls and collection of a 2nd day 24-hour recall by telephone. For the analyses of mean intakes, only the first 24 hour recall is used. Each respondent was asked to recall the kinds and amounts of foods eaten at home and away from home during the previous day. Amounts of foods reported in household measures were then converted to gram amounts.
Estimates were calculated using the USDA MyPyramid Equivalents Database. Solid fats are defined in the MyPyramid Equivalents Database as all excess fat from milk and meat beyond what would be consumed if only the lowest fat forms were eaten and those added to foods in preparation or at the table, including cream, butter, stick margarine, regular or low-fat cream cheese, lard, meat drippings, cocoa, chocolate, hydrogenated fats, and those derived from palm or coconut oils. This definition includes dietary sources of trans as well as saturated fatty acids.
Breast-fed children are excluded from the numerator and denominator.