Factors associated with weight gain during the COVID-19 pandemic

Background: To limit transmission of COVID-19, state governments issued shelter-in-place orders. These orders coincided with a decrease in daily step count and an increase in overeating. We evaluated factors associated with weight gain of > 15 pounds during the pandemic within an integrated health care system.Methods: We included adults ages 18 and above with at least one weight measurement before the pandemic (March 19, 2019-March 19, 2020) and another measurement after COVID-19 vaccines became available, more than 9 months into the pandemic (December 14, 2020-December 14, 2021). Logistic regression was used to identify factors associated with weight gain of 15 pounds or more.Results: Of 524,451 adults included in the study, median age was 61 years, 43.2% were men, 36.2% self identified as White, 8.6% Black, 35.7% Hispanic, and 16.2% Asian. During the pandemic, 38,213 (7.3%) adults gained > 15 pounds. A higher proportion of young adults gained weight (16.2% age 18-39, 7.6% age 40-64, 4.7% age 65-79%, and 3.1% age > 80). No significant difference was observed between men and women (7.2% men and 7.4% women). Weight gain was more prevalent among adults from low-income neighborhoods (8.9% low-income neighborhoods, 8.0% intermediate-income neighborhoods, and 6.5% high-income neighborhoods). Multivariable logistic regression demonstrated that compared to adults ages 65-79 years, young adults ages 18-39 years had the highest risk of gaining > 15 pounds (adjusted OR 5.19, 95% CI 5.01-5.38). Black race was associated with weight gain in an unadjusted analysis (OR 1.25, 95% CI 1.21-1.30). However, this association was significantly attenuated after adjusting for other risk factors including neighborhood income levels (adjusted OR 1.06, 95% CI 1.02-1.10). Having a diagnosis of depression pre-pandemic was also associated with weight gain during the pandemic (adjusted OR 1.54, 95% CI 1.50-1.58).Conclusion: In this racially and ethnically diverse population in southern California, significant weight gain of 15 pounds or more was observed in 7.3% of the adult population during the COVID-19 pandemic. Young adults, individuals who resided in low-income neighborhoods, and patients with depression were disproportionally affected.