Abstract

BACKGROUND:

Obesity is related to many adverse health-related outcomes.

OBJECTIVE:

We investigated whether changes in physical activity were related to less gain in either body weight or waist circumference (WC).

DESIGN:

The association between prospectively assessed physical activity and either body weight or WC was examined in 4944 participants of the Doetinchem Study (men and women aged between 26 and 66 y at baseline). Information on physical activity (derived from a validated physical activity index), body weight, and WC, measured according to standardized procedures, was collected at baseline and at the 5- and 10-y follow-ups.

RESULTS:

Random mixed-effects models showed that a single measurement of physical activity was not clearly related to change in body weight and WC over a 5-y period. However, analyses of repeated measures showed that compared with those who maintained their activity level, those who increased their physical activity over a 5-y period had less gain in WC ( minus 0.35 cm; 95% CI: minus 0.65, minus 0.05 cm) and possibly in body weight ( minus 280 g; 95% CI: minus 620, 5 g). Most importantly, these effects were sustained (although not significantly) in the consecutive 5 y for WC ( minus 0.56 cm; 95% CI: minus 108, 0.04 cm) and for body weight ( minus 590 g; 95% CI: minus 1005, minus 130 g), which indicated that physical activity was truly a determinant of body size changes.

CONCLUSIONS:

An increase in physical activity was associated with a statistically significant lower gain in body weight and in WC, which was maintained during the following 5 y. These findings support the need for public health programs that promote physical activity.