Assessment of the physical activity level with two questions: validation with doubly labeled water

Int J Obes (Lond). 2008 Jun;32(6):1031-3. doi: 10.1038/ijo.2008.42. Epub 2008 Apr 8.


Objective: To validate a two-question questionnaire on physical activity with the doubly labeled water (DLW) method.

Design: Cross-sectional study.

Subjects: Nine volunteers, age 33-75 years, with a mean body mass index (BMI) (kg m(-2)) of 27.4.

Measurements: A questionnaire with one question on physical activity at work and one question on physical activity during leisure time. The answers were converted into a PAL (physical activity level=energy expenditure/basal metabolic rate) value, which was validated with the DLW method.

Results: The mean values (s.d.) of PAL for the questionnaire and DLW measurements were 1.7 (0.1) and 1.7 (0.1), respectively, with a mean difference of 0.004 (0.172).

Conclusions: The results were promising to the extent that they could be used in large-scale epidemiological studies.

Publication types

  • Validation Study

MeSH terms

  • Adult
  • Aged
  • Basal Metabolism / physiology
  • Employment
  • Energy Metabolism / physiology*
  • Female
  • Humans
  • Leisure Activities
  • Male
  • Mass Spectrometry
  • Middle Aged
  • Physical Exertion / physiology*
  • Radioisotope Dilution Technique
  • Reproducibility of Results
  • Surveys and Questionnaires / standards*
  • Water


  • Water