Liu, Jie

Objectives To observe the weight change in Chinese youth during a 4-month COVID-19 lockdown, and the association between weight change and mental health, physical activity and sedentary time changes, and dietary habits. Design A retrospective observational study. Settings Two universities located in Zhejiang and Hunan provinces, China. Participants This study enrolled 12 889 college students whose body weight was measured before the lockdown (1 December 2019–20 January 2020) at the two universities, and reported their weight measured at home or community after the end of the lockdown (1–23 May 2020) via an online follow-up questionnaire. Primary and secondary outcome measures The primary outcome was the weight change in Chinese youth during a 4-month lockdown resulting from the COVID-19 pandemic. The secondary outcomes were the relationships of weight change to COVID-19-related stress, depression, anxiety, physical activity and sedentary time changes, and dietary habits. Results Participants’ ages ranged from 17 to 27 years ( M =19, SD=1) with 80.2% identified as female. The average absolute and relative changes in body weight were 2.6 (95% CI 2.0 to 3.2)) kg and 4.2% (95% CI 4.0% to 4.3%) for men, and 2.1 (1.9 to 2.4) kg and 4.2% (95% CI 3.9% to 4.4%) for women. An increase in overweight and obese individuals according to Asian cut-off points as a demographic percentage by 4.5% and 2.7% and 4.8% and 3.4% in men and women, respectively ( P <0.001), was observed. Weight gain was significantly associated with increased sedentary time and an increase in COVID-19-related stress and depression score. Conclusion The present study’s results suggest that the risk of weight gain in Chinese youth during the lockdown increased and that strategies to decrease sedentary time and improve mental health may be warranted to mitigate weight gain during and after the COVID-19 pandemic.

Abstract The COVID-19 (coronavirus disease-19) has resulted in nationwide lockdowns, cessation of school and work, and social distancing. Reducing the negative impacts, such as weight-gain, has garnered global attention. In this dual-center prospective cohort study of 12,889 students, we assessed weight-gain in a youth during the 4-month COVID-19 lockdown, and examined the associations between weight-gain and COVID-19 induced stress, depression and self-reported physical activity, dietary habits and sedentary time. Participants gained an average of 2.6 kg (95% CI: 2.0 to 3.2 kg) for males and 2.1 kg (1.9 to 2.4 kg) for females. An increase in overweight and obese individuals as a demographic percentage by 4.5% and 2.7% and 4.8% and 3.4% in males and females respectively (P<0.001). Weight change was independently associated with severe COVID-19 induced stress, sedentary time, and depression score. Techniques to relieve COVID-19 induced stress, reduce sedentary time through increased physical activity, and improve dietary habits in youth may be warranted to help prevent and/or reverse weight-gain associated with the lockdown period of COVID-19.Registration: Registered with ChiCTR, registration no.: ChiCTR2000033514