Objective This systematic review and meta‐analysis aimed to examine: the pooled prevalence of symptomatic behaviours and mental health deterioration amongst individuals with eating disorders (EDs) and obesity during the COVID‐19 confinement. Moreover, we examined changes in EDs and distress before and during the confinement, and the association between psychosocial factors and EDs symptoms. Method A systematic search was carried out in biomedical databases from January 2020 to January 2021. Both cross‐sectional and longitudinal studies that used quantitative measures of ED symptoms and psychological distress during and after the COVID‐19 confinement were included. Results A total of 26 studies met inclusion criteria (n = 3399, 85.7% female). The pooled prevalence of symptomatic deterioration in EDs was 65% (95% CI48,81, k = 10). The pooled prevalence of increased weight in obesity was 52% (95% CI25,78, k = 4). More than half of the participants experienced depression and anxiety. Moreover, at least 75% of the individuals with EDs reported shape and eating concerns, and increased thinking about exercising. However, the pooled analyses of longitudinal studies showed no significant differences from pre‐pandemic levels to the first lockdown phase in Body Mass Index and ED symptoms, whereas only few studies suggested increased distress, particularly among individuals with anorexia nervosa. Conclusions The majority of individuals with EDs and obesity reported symptomatic worsening during the lockdown. However, further longitudinal studies are needed to identify vulnerable groups, as well as the long‐term consequences of COVID‐19. Key points Sixty‐five percent of the individuals with Eating Disorders experienced symptom deterioration during the COVID‐19 confinement Fifty‐two percent of the individuals with obesity reported weight increase More than half of the participants experienced depression and anxiety However, the few studies that examined changes in symptoms before and during the confinement showed inconsistent findings High‐quality longitudinal studies are needed to identify vulnerable groups, as well as the long‐term impact of COVID‐19