Endocrine Abstracts

Objective: To evaluate the associations between baseline leisure-time physical activity (LTPA) or changes in LTPA during follow-up on long-term weight changes, and to investigate the effects of physical activity in participants with baseline BMI<25 kg/m² and baseline BMI≥25 kg/m².

Material and methods: Data of the prospective dynamic cohort (SUN cohort) were used. In total 12 117 participants, all of them university graduates, were followed-up for an average time of 27 months. Baseline LTPA was assessed with a previously validated questionnaire. We used self-reported data of body mass index (BMI), and a semiquantitative food-frequency questionnaire, both had been validated. The study was approved by the local Ethical Committee.

Results: After adjusting for age, smoking status, total energy intake, snacking, hours sitting down, alcohol intake, total fiber intake, the consumption of sugar sweetened beverages and fast food, participants who decreased their LTPA during follow-up experienced a significant (P<0.001) increase in body weight: (+0.70 kg for men, +0.64 kg for women). Participants who increased their LTPA during follow-up experienced a significant (P<0.001) reduction in body weight: (−0.66 kg for men, −0.39 kg for women). This inverse association between changes in LTPA and weight change was stronger for participants with a baseline BMI≥25 kg/m² (P=0.005 for interaction in males and P=0.01 for interaction in females).

Conclusion: Longitudinal changes in LTPA during follow-up are inversely associated with changes in body weight, particularly in participants with initial BMI≥25 kg/m². This association is apparently stronger than that between baseline LTPA and weight change.