question: BACKGROUND: Quarantine/confinement is an effective measure to face the Coronavirus disease 2019 (COVID-19). Consequently, in response to this stressful situation, people confined to their homes may change their everyday eating behavior. Therefore, the primary objective of this study is to evaluate the association between quarantine/confinement stressors and eating behavior during the COVID-19 outbreak. The secondary objective is to compare the association of quarantine/confinement stressors and diet behavior between two groups of participants, those attending diet clinics and those not (general population). METHOD: A cross-sectional web-based online survey carried out between April 3 and 18, 2020, enrolled 407 participants from the Lebanese population. Eating Disorder Examination – Questionnaire (EDE-Q) were used to measure the behavioral features of eating disorders. RESULTS: More than half of the sample (53.0%) abide by the home quarantine/confinement, 95.4% were living with someone in the quarantine/confinement, and 39.6% continued to work from home. Higher fear of COVID-19 was found in 182 (44.8%) participants, higher boredom in 200 (49.2%) participants, higher anger in 187 (46.3%), and higher anxiety in 197 (48.5%) participants. Higher fear of COVID-19 (Beta = 0.02), higher BMI (Beta = 0.05), and physical activity (Beta = 1.04) were significantly associated with a higher restraint score. Higher anxiety, higher fear of COVID-19, higher BMI, practicing physical exercise, and a higher number of adults living in the quarantine/confinement were significantly associated with higher shape and weight concerns. CONCLUSION: Our results showed that the fear of COVID-19 was correlated with more eating restraint, weight, and shape concerns in the whole sample, but more specifically in the dietitian clients group. Public health control measures are needed to reduce the detrimental effects of psychological distress associated with quarantine/confinement on eating behaviors during the COVID-19 outbreak.