• 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)
  • WHQ030 - How do you consider your weight
  • WHQ040 - Like to weigh more, less or same
  • WHD050 - Self-reported weight - 1 yr ago (pounds)
  • WHQ055 - CHECK ITEM
  • WHQ060 - Weight change intentional
  • WHQ070 - Tried to lose weight in past year
  • WHD080A - Ate less to lose weight
  • WHD080B - Switched to foods with lower calories
  • WHD080C - Ate less fat to lose weight
  • WHD080D - Exercised to lose weight
  • WHD080E - Skipped meals
  • WHD080F - Ate diet foods or products
  • WHD080G - Used a liquid diet formula
  • WHD080H - Joined a weight loss program
  • WHD080I - Took prescription diet pills
  • WHD080J - Took non-RX suppl. to lose weight
  • WHD080K - Took laxatives or vomited
  • WHD080M - Drank a lot of water
  • WHD080N - Followed a special diet
  • WHD080O - Ate fewer carbohydrates
  • WHD080P - Started to smoke or began to smoke again
  • WHD080Q - Ate more fruits, vegetables, salads
  • WHD080R - Changed eating habits
  • WHD080S - Ate less sugar, candy, sweets
  • WHD080T - Ate less junk food or fast food
  • WHD080U - Had weight loss surgery to lose weight
  • WHD080L - Other
  • WHQ225 - Times lost 10 lbs or more to lose weight
  • WHQ105 - CHECK ITEM
  • WHD110 - Self-reported weight-10 yrs ago (pounds)
  • WHQ115A - CHECK ITEM
  • WHD120 - Self-reported weight-age 25 (pounds)
  • WHQ125 - CHECK ITEM
  • WHD130 - Self-reported height - age 25 (inches)
  • WHD140 - Self-reported greatest weight (pounds)
  • WHQ150 - Age when heaviest weight

National Health and Nutrition Examination Survey

2017-March 2020 Data Documentation, Codebook, and Frequencies

Weight History (P_WHQ)

Data File: P_WHQ.xpt

First Published: November 2021

Last Revised: NA

Component Description

The NHANES program suspended field operations in March 2020 due to the coronavirus disease 2019 (COVID-19) pandemic. As a result, data collection for the NHANES 2019-2020 cycle was not completed and the collected data are not nationally representative. Therefore, data collected from 2019 to March 2020 were combined with data from the NHANES 2017-2018 cycle to form a nationally representative sample of NHANES 2017-March 2020 pre-pandemic data. These data are available to the public. Please refer to the Analytic Notes section for more details on the use of the data.

The Weight History section of the Sample Person Questionnaire (variable name prefix WHQ) provides personal interview data on several topics related to body weight, including self-perception of weight, self-reported weight over the participant’s lifetime, attempted weight loss during the past 12 months, and methods used to try to lose weight and to keep from gaining weight.

Eligible Sample

Participants aged 16 years and older in the NHANES 2017-March 2020 pre-pandemic sample were eligible. However, eligibility varies by age for some questions. Please review the codebook carefully. Frequency counts were verified during the preparation of the file.

Interview Setting and Mode of Administration

Trained interviewers asked these questions, in the home, using the Computer-Assisted Personal Interview (CAPI) system.

For details on the administration of the WHQ_J, 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.”

If maximum weight (WHQ150) extended over more than one year, the interviewer recorded the most recent age at which the survey participant reported that weight.

All responses to WHQ150 (age when weighed the most) of 80 years and older were coded as “80” to be consistent with the way age of the survey participant was coded in the demographic file.

Analytic Notes

The COVID-19 pandemic required suspension of NHANES 2019-2020 field operations in March 2020 after data were collected in 18 of the 30 survey locations in the 2019-2020 sample. Data collection was cancelled for the remaining 12 locations. Because the collected data from 18 locations were not nationally representative, these data were combined with data from the previous cycle (2017-2018) to create a 2017-March 2020 pre-pandemic data file. The resulting sample weights in the demographic file should be used to calculate estimates from the combined cycles. These sample weights are not appropriate for independent analyses of the 2019-2020 data and will not yield nationally representative results for either the 2017-2018 data alone or the 2019-March 2020 data alone. Please refer to the NHANES website for additional information for the NHANES 2017-March 2020 pre-pandemic data, and for the previous 2017-2018 public use data file with specific weights for that 2-year cycle.

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