Background and objective:
The COVID-19 pandemic led to social isolation as a non-pharmacological intervention measure. Despite being an effective strategy for reducing transmission of the disease, research has indicated the occurrence of changes in lifestyle and negative repercussions on the health of populations. The objective was to associate changes in physical activity and the perception of weight gain during the COVID-19 pandemic in ELSA-Brasil.

Methods:
Longitudinal study using the second follow-up of the cohort (2017-18) and Onda-Covid (2020-21) that included civil servants residing in 5 Brazilian capitals. Socioeconomic and lifestyle data were collected. Leisure-time physical activity (LPA) was measured using the International Physical Activity Questionnaire, converted into multiples of metabolic equivalents (METs/week) and classified into tertiles of change. The association between changes in LPA and perceived weight gain was verified by obtaining crude and adjusted odds ratio estimates and 95% confidence intervals using binary logistic regression.

Results:
The final sample consisted of 3,940 individuals, 58.8% women. Participants who reported weight gain had lower mean age, diet quality and LPA, and higher mean body mass index. When analyzing the LPA change delta between assessments, there was a reduction in the mean METs/week in both genders (p<0.001). Being in the low tertile of LPA change increased the odds of perceived weight gain by 1.5 (95% CI 1.04-1.45) and 1.6 95% (CI 1.04-1.45) times among women and men, respectively.

Conclusion:
Women and men in the lowest tertile of LPA change were more likely to perceive weight gain during COVID-19.