Dun Y, Ripley-Gonzalez JW, Zhou N, et al. - A retrospective observational study was conducted to explore 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. Researchers recruited a total of 12,889 college students whose body weight was assessed before the lockdown (1 December 2019–20 January 2020) at the two universities and reported their weight assessed at home or community after the end of the lockdown (1–23 May 2020) via an online follow-up questionnaire. The results showed that during the lockdown, the risk of weight gain in Chinese youth 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.