Article Title



R.P. McGrath*, A.J. Moshfegh**, M. Kramer**, W.V. Rumpler**, D.J. Baer**, C.A. Vella*, P.W. Scruggs*, & D.R. Paul*

*University of Idaho, Moscow, ID; **U.S. Department of Agriculture, Beltsville Human Nutrition Research Center, Beltsville, MD

The NHANES physical activity questionnaire (PAQ) is a popular self-report method for measuring physical activity, although the validity of total energy expenditure (TEE) and moderate-to-vigorous physical activity (MVPA) estimates have yet to be validated. PURPOSE: To compare estimates of TEE (TEE-PAQ) and MVPA (MVPA-PAQ) from the NHANES PAQ with TEE via doubly labeled water (TEE-DLW), and total physical activity (TPA) and MVPA (MVPA-A) via accelerometer. METHODS: 244 women (age 49.2 ±10.8 yrs. and BMI 26.2 ± 4.85 kg/m2) and 242 men (age 49.7 ±11.0 yrs. and BMI 26.7 ± 4.08 kg/m2) completed the NHANES PAQ (2001 version). TEE was measured by the doubly labeled water technique over a 2-week period. TPA and MVPA-A were measured via accelerometer for a minimum of 7 days. T-tests were conducted to compare differences between TEE-PAQ and TEE-DLW, and MVPA-PAQ and MVPA-A. To compare the predictions of TEE-PAQ and TEE-DLW, regression analyses were conducted utilizing TPA and body weight as independent variables.

RESULTS: TEE-PAQ (9.61 ± 2.60 MJ/d) was significantly lower than TEE-DLW (10.6 ± 2.38 MJ/d) (pThese data indicate that the NHANES PAQ underestimates TEE when compared to doubly labeled water (1.0 MJ/d), with a large amount of variability present (2.17 MJ/d on average per subject). The lower residual variance in the comparison between TEE-DLW and TPA (when compared to TEE-PAQ and TPA) indicate that TEE-PAQ may be the less valid approach. Similarly the PAQ overestimates MVPA by 11.2 min/d when compared to accelerometry, with an average error of 21.1 min/d per subject. Therefore, estimates of TEE and MVPA from the NHANES PAQ should be interpreted with caution.

This study was funded by the USDA.

This document is currently not available here.