Objectives Lockdown measures have been adopted in many countries around the world to control the spread of COVID-19. These measures induced long confinement period that may have had an unintended negative impact on children's life behaviors and health. This study aimed to investigate the impact of behaviors related to COVID-19 confinement on body weight/BMI changes in children from Constantine, Algeria. Methods This was a cross-sectional survey based on children aged 5 to 12 years dwelling in any province of Constantine. Parents of children completed an online-distributed questionnaire at two time points (between April and May and anther time between 11th July and 10th august 2020). The questionnaire assessed sociodemographic information, anthropometric data, physical activity, dietary, eating habits, and other factors related to children’s lifestyle before and during lockdown. Paired before and during lockdown comparison for each lifestyle multiple statistic tests were performed to assess associations among before and during lockdown data. Results 275 questionnaires were completed (59.7%). Mean self-reported weight and BMI significantly increased by 1.43 kg and 0.84 kg/meter 2, respectively. Among the examined variables, increased unhealthy food consumption, snacks, number of daily meals taken, low physical activity and increased sedentary behaviors were significantly correlated with higher body weight gain (P < 0.005). These behaviors may not only have a significant impact on the development of childhood obesity but also on the deterioration of the mental state of the children surveyed. Conclusion Restrictive measures during the COVID-19 lockdown, and home confinement, school closure makes children more vulnerable to environmental risks. Results from this study highlight the risk associated with a shift in eating habits, increased dietary intake, decreased physical activity, increased sedentary behaviors, and their impact in exacerbating the gain in body weight and BMI. Supplementary Information The online version contains supplementary material available at 10.1007/s10995-022-03441-2.

The lockdown caused major upheavals in everyone's life and a considerable public health burden. These changes are bound to lead weight gain and increase the rate of obesity around the world. The aim of the present survey was to determine the impact of the COVID-19 lockdown on global health in a population of adults from Constantine, Algeria. More precisely, the survey aimed at determining factors associated with obesity, as well as a comparison of the lifestyle changes and habits of this population before and during the COVID-19 lockdown. The questionnaire was deployed via an Algerian electronic platform named "Word Form" and shared its link on social networks. A total of 1400 subjects completed the survey and after validation of the data, 1000 respondents have been included in the study. The age of our population was >19 years old. About 45% of the participants declared that their diet became imbalanced during the COVID-19 lockdown (P=0.016). In contrast, 63% admitted to snacking after dinner and 74% snaking between meals represented a high association which weight gain (P<0.01). The results suggests that poor sleeping patterns can lead to weight gain and an increase in body mass index (P <0.01). The COVID-19 pandemic had a serious impact on the eating habits and lifestyle changes during the pandemic after the lockdown period in an adult Algerian population.