The aim of this study is to assess lifestyle changes along with weight fluctuations during the COVID-19 lockdown in Lebanon. This cross-sectional study was conducted using a web-survey disseminated through social media platforms to a large sample of the Lebanese population between May 25th and June 8th, 2020, during the lockdown in Lebanon. Behavioral changes and weight variation during the confinement were assessed. Two thousand one hundred sixty-one participants (64.9% female) aged 18 to 78years old were included in this study. On average, no net weight variation was reported by the participants. 59.3% of the smokers changed their smoking habits, 40.7% of the drinkers reported a decrease in alcohol consumption, 43.5% of the participants exercised less than one time weekly and 35.8% changed their diet. Increased frequency of physical activity, following a diet during lockdown, decreased weight dissatisfaction (P<0.0001 for the three variables) were retained as significant factors associated with weight loss. Planning to engage in physical activity post lockdown was associated with weight gain (P=0.021). In the Lebanese population, no net weight variation was reported during the lockdown. Increasing physical activity and initiating diet were associated with weight loss. Healthcare authorities should be alerted about the importance of these factors during the follow-up of the confined population.