The Impact of the COVID-19 Pandemic: A Longitudinal Analysis of Body Weight Variations and Their Implications for Daily Habits

Assessing changes in lifestyle, dietary habits, eating behaviors, and stress during the pandemic and their impact on weight is crucial for developing effective interventions. This study investigated weight variations among Brazilians and associated habit changes over nine months during the COVID-19 pandemic. An online questionnaire was applied (T0/T1, T2). Weight variation classifications were determined from T0 to T1 and evaluated longitudinally for changes in lifestyle, dietary habits, food consumption, eating behavior, and perceived stress using generalized estimating equations (<i>p</i> < 0.05). Out of 453 participants, 23.6% lost weight, 18.1% maintained their weight, 26.0% gained up to 2.4 kg, and 32.2% gained ≥ 2.5 kg. Weight loss was associated with decreased food consumption and increased stress at T2. The group that gained up to 2.4 kg reported reduced food intake, snacking, meal preparation, and candy consumption but increased stress at T2. Those gaining ≥ 2.5 kg initially increased food consumption, snacking, meal preparation, hamburgers/canned products, sugary drinks, instant meals/snacks, candies, and fast food consumption at T1, all of which were reduced at T2, along with a decrease in uncontrolled and emotional eating. Although the pandemic initially affected daily habits differently based on weight changes, participants-especially those who gained more weight-tended to revert to pre-pandemic habits.