The effects of COVID-19 lockdown on the body weight and lifestyle behaviors of U.S. adults

The COVID-19 pandemic and associated policies may have impacted body weight and related lifestyle behaviors. Using 2017–2020 Behavioral Risk Factor Surveillance System data, we estimate the effects of COVID-19 lockdown on Body Mass Index (BMI) and the probability of obesity among adults in the United States. Our triple-differences approach, using recent pre-pandemic years as counterfactuals, identifies statistically significant lockdown-induced increases in body weight. Event study results highlight a lagged effect of lockdown on body weight, with BMI increases manifesting 2 months post-lockdown. These effects are particularly pronounced among non-white adults, low-income individuals, females, and metropolitan residents. The lockdown's impact on mental health, a potential mechanism driving BMI increases, is concentrated among non-white, low-income adults. We observe potential post-lockdown changes in diet and sedentary behaviors, evidenced by increased Google searches for high-calorie foods, food delivery apps, and video streaming. Google searches related to healthy habits, such as exercise, yield mixed results.