• Component Description
• Eligible Sample
• Interview Setting and Mode of Administration
• Quality Assurance & Quality Control
• Data Processing and Editing
• Analytic Notes
• Codebook
  • SEQN - Respondent sequence number
  • WHD010 - Current self-reported height (inches)
  • WHD020 - Current self-reported weight (pounds)
  • WHD050 - Self-reported weight - 1 yr ago (pounds)
  • WHQ070 - Tried to lose weight in past year

National Health and Nutrition Examination Survey

August 2021-August 2023 Data Documentation, Codebook, and Frequencies

Weight History (WHQ_L)

Data File: WHQ_L.xpt

First Published: September 2024

Last Revised: NA

Component Description

The Weight History section of the Sample Person Questionnaire (variable name prefix WHQ) provides personal interview data on several topics related to body weight and height, including self-reported weight   and height, self-reported weight a year ago and attempted weight loss during the past 12 months.

Eligible Sample

Participants aged 16 years and older were eligible. Please review the codebook carefully. Frequency counts were verified during the preparation of the file.

Interview Setting and Mode of Administration

These questions were asked, in the home or by telephone, by trained interviewers using the Computer-Assisted Personal Interview (CAPI) system. For details on the administration of the WHQ_L, please refer to the Weight History Sample Person Questionnaire on the NHANES website.

Quality Assurance & Quality Control

The CAPI system is programmed with built-in consistency checks to reduce data entry errors. CAPI also uses online help screens to assist interviewers in defining key terms used in the questionnaire.

Data Processing and Editing

Edits were made to some variables to ensure the completeness, consistency, and analytic usefulness of the data. Edits were also made, when necessary, to address data disclosure concerns. When a variable was modified globally, as part of the editing process, the third letter in the variable name was changed from a Q (i.e., WHQ) to a D (i.e., WHD). For example, height data were collected as feet and inches, but standardized to inches using the conversion factors 0.3937 inches per centimeter and 12 inches per foot. Current and past self-reported weights were standardized to weight in pounds using the conversion factor 2.2046 pounds per kilogram.

Reported heights and weights, considered being physiologically implausible or the result of interviewer data entry error, were coded as “missing.” 

Analytic Notes

Although data in this file were collected as part of the household interview, if they are merged with the MEC exam data, exam sample weights should be used for analyses.

Please refer to the NHANES Analytic Guidelines and the on-line NHANES Tutorial for further details on the use of sample weights and other analytic issues. 

Codebook and Frequencies