Reduce consumption of saturated fat by people aged 2 years and over — NWS‑11 Data Methodology and Measurement

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.

NHANES includes 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. To reduce in person contact during the COVID-19 pandemic, for the August 2021–August 2023 cycle, the 1st 24-hour recall was also conducted by telephone. For the analyses of mean intakes, only the first 24 hour recall is used. Each respondent is 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 are then converted to gram amounts, and saturated fat intake estimated with the use of food composition files. Both dietary recalls are obtained by trained dietary interviewers using USDA's Automated Multiple Pass Method (AMPM). Estimates are calculated using the USDA Food Patterns Equivalents Database (FPED).

Breast-fed children are excluded from the numerator and denominator.

Design changes were made to the August 2021-2023 NHANES cycle to minimize in-person contact during the COVID-19 pandemic. Refer to the Data Source page for more information. Unlike previous cycles, there was no oversampling of persons with family incomes <185% of the poverty threshold. This may result in lower confidence in the estimate and insufficient power to detect differences between groups. In addition, seventeen percent of interview participants had missing family income data.