Synergistic effects of COVID-19 pandemic and sedentary lifestyles on obesity rates among South Korean adults

Abstract

Since March 2020, South Korea has implemented social distancing measures to reduce the spread of the coronavirus disease (COVID-19). These policies resulted in significant changes in the lifestyle of Korean adults, including spending more time indoors and experiencing increased sedentary time during the pandemic. This study aimed to investigate the combined influence of sedentary lifestyle and the COVID-19 pandemic on obesity rates among adults residing in South Korea. Data were obtained from the 2018-2020 Korea National Health and Nutrition Examination Survey (KNHANES). Multiple logistic regression was used to analyze the synergistic effects of a sedentary lifestyle and COVID-19 on obesity. The prevalence of sedentary lifestyles among the participants increased from 30.4% pre-COVID-19 to 36.6% during the pandemic. Furthermore, the obesity rates were raised independently by COVID-19 (OR: 1.16, 95% CI 1.04-1.30) and by a sedentary lifestyle (OR = 1.17, 95% CI 1.04-1.31). A synergistic effect of a sedentary lifestyle and COVID-19 on obesity was identified (OR: 1.57, 95% CI 1.30-1.85). COVID-19 and a sedentary lifestyle significantly increased the risk of obesity in South Korean adults. Moreover, the combined synergistic effects of these risk factors were too substantial to be disregarded by merely summing their individual effects on obesity.The COVID-19 outbreak has had considerable global consequences. Over 200 million confirmed cases and 4 million deaths were reported within 18 months of the onset of the pandemic 1 . South Korea had the first case confirmed on January 20, 2020. The virus quickly spread, resulting in 6284 confirmed cases and 42 deaths in less than 1 month 2 . Thus, the South Korean government implemented rigorous social distancing measures from February 29, 2020, to mid-2022 to prevent the spread of the outbreak 3 . These measures involve contact tracing, quarantine, social distancing, and remote working, which cause significant lifestyle changes.Owing to social distancing, people spent more time indoors and prolonged sedentary behavior compared to pre-pandemic times 4,5 . According to a recent systematic review, 64 studies reported an increase in sedentary behavior during the respective COVID-19 pandemic closures in various populations, including children and patients with a variety of medical conditions 6 . Sedentary behavior is associated with a range of adverse health outcomes, including changes in the circulatory levels of sex hormones and considerable weight gain 5,7,8 . Obesity has emerged as a leading contributor to poor health 9 , with significant impacts on the quality of life, and an increased risk of serious medical complications, such as cardiovascular disease, musculoskeletal disorders, and various types of cancers 10 .All 40 studies from different countries included in a systematic review reported changes in body weight during the pandemic, and most showed weight gain among participants 11 . The obesity rate among South Korean adults (Body Mass Index (BMI) ≥ 25) steadily increased f...