title: Effect of change in physical activity on body fatness over a 10-y period in the Doetinchem Cohort Study.
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).
  
  
  METHODS
  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.
authors.affiliation: National Institute for Public Health and the Environment, Bilthoven, Netherlands. a.m.may@umcutrecht.nl
authors.forename: Anne M
authors.initials: AM
authors.lastname: May
authors.forename: H Bas
authors.initials: HB
authors.lastname: Bueno-de-Mesquita
authors.forename: Hendriek
authors.initials: H
authors.lastname: Boshuizen
authors.forename: Annemieke M W
authors.initials: AM
authors.lastname: Spijkerman
authors.forename: Petra H M
authors.initials: PH
authors.lastname: Peeters
authors.forename: W M Monique
authors.initials: WM
authors.lastname: Verschuren
mesh_terms: D000328:Adult; D000368:Aged; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009426:Netherlands; D009765:Obesity / Q000517:prevention & control*; D011446:Prospective Studies; D055105:Waist Circumference / Q000502:physiology*; D015430:Weight Gain / Q000502:physiology*