CDC-Led Study Details Weight Gain Trends During COVID-19 Pandemic

Heidi Blanck, PhD, MS

New research from a team at the US Centers for Disease Control and Prevention (CDC) is providing insight into the trends in weight gain among the general population of adults in the US during the early stages of the COVID-19 pandemic.

Results of the study, which leveraged electronic medical record data from 4,250,000 adult patients, demonstrate there was a 0.1 kg increase in weight gain during the first year of pandemic compared to prepandemic weight gain trends. Results also detail changes in weight gain trends were observed varying across sex, age, and initial BMI categories, with the greatest weight increases observed among women, adults with a BMI of 30 or 35 kg/m², and younger adults.

“Although weight changes varied by sex, age, and initial BMI, the maximum excess weight gain across various combinations of these characteristics was 1.3 kg among 25-year-old women with BMIs of 30 or 35 kg/m² in the first year of the pandemic. Adult weight gain during the pandemic may be much less than the amount suggested by several initial reports,” wrote investigators.

Prior to the COVID-19 pandemic, the obesity epidemic was on its way to taking center stage in the public eye. Although COVID-19 has dominated headlines from early 2020 and on, the focus on obesity has grown as well since it was identified as a major risk factor for severe COVID-19. With previous reports pointing to concerning trends in inactivity and weight gain during the pandemic, but these studies being limited by design and sample size, a team led by Heidi M. Blanck, PhD, chief of the Obesity Prevention and Control Branch of the CDC, designed their study to compare trends in weight gain prepandemic to the early stages of pandemic using the IQVIA Ambulatory Electronic Medical Records database.

From this database, investigators obtained data from 4.25 million adult patients aged 18-84 years with 2 or more visits in the prepandemic period, which was defined as January 1, 2019-February 28, 2020, and at least a single visit after June 1, 2020. The cohort consisted of 1,745,530 male subjects with a mean age of 58.6±15.0 at first exam and 2,500,471 female subjects with a mean age of 54.5±16.7 years at first exam. The overall cohort had a mean BMI of 30.5 kg/m2 and 46% of patients had obesity, with 8% of men and 11% of women having a BMI of 40 kg/m2 or greater.

Initial analysis revealed the mean initial weight of male subjects decreased by 0.5 kg between the first and last examinations while an increase of 0.1 kg was observed for mean weight of female subjects between the first and last examinations. When assessing longitudinal change in weight between their last visit during the pandemic and the last visit after the pandemic, which had mean dates of December 7, 2019, and January 17, 2021, respectively, 15% of subjects lost more than 5% of the prepandemic weight and 16% gained more than 5% of their prepandemic weight. Among these groups, the mean weight changes were -9.0 kg and 7.7 kg, respectively.

“Although the COVID-19 pandemic had a significant impact on individuals' lives, livelihoods, and behaviors, we found little weight change among adults associated with the first year of the pandemic. Compared with expected weight changes based on prepandemic trends, there was a small increase in weight among the 4.25 million adults in our study,” investigators wrote.

This study, “Weight Gain Among U.S. Adults during the COVID-19 Pandemic through May 2021,” was published in Obesity.