Abstract:Background and aims Obesity is a major global health challenge, and laparoscopic sleeve gastrectomy (LSG) is a widely used bariatric procedure. However, weight loss outcomes vary considerably among patients. Psychological factors and eating behaviors are increasingly recognized as important determinants of postoperative success, yet the underlying mechanisms remain unclear. This study aimed to examine the relationship between self-control and 12-month postoperative weight loss (%EWL) after LSG, and to test the independent and chain mediating roles of depression and emotional eating.Methods In a cross-sectional study, 202 LSG patients from the Third Xiangya Hospital of Central South University completed the Brief Self-Control Scale (BSCS), Patient Health Questionnaire-9 (PHQ-9), and the emotional eating subscale of the Dutch Eating Behavior Questionnaire (DEBQ). %EWL within 12 months after surgery was calculated. Pearson correlations were conducted, and mediation was tested using Process v4.0 (model 6) with 5 000 bootstrap samples while controlling for sex and postoperative time.Results Overall, BSCS, PHQ-9, DEBQ-EE, and %EWL averaged 21.76±4.15, 5.54±3.91, 30.72±11.25, and (60.94±31.61)%, respectively. Self-control correlated negatively with depression (r=-0.697) and emotional eating (r=-0.441) and positively with %EWL (r=0.566; all P<0.01). %EWL correlated negatively with depression (r=-0.467) and emotional eating (r=-0.348, P<0.01). Adjusted regression showed positive prediction of %EWL by self-control (β=0.291 9, P<0.01) and negative prediction by depression (β=-0.155 6, P<0.05) and emotional eating (β=-0.115 8, P<0.05). Mediation analysis showed that the indirect effect through the path "self-control → depression → %EWL" was 0.848 8 (95% CI=0.178 7-1.573 0). The indirect effect through the path "self-control → emotional eating → %EWL" was 0.259 8 (95% CI=0.033 4-0.564 3). The chain indirect effect through the path "self-control → depression → emotional eating → %EWL" was 0.131 7 (95% CI=0.005 9-0.322 8); the total indirect effect accounted for 35.83% of the total effect.Conclusion Higher self-control after LSG enhances weight loss both directly and indirectly by alleviating depression and emotional eating. Routine psychological screening and eating-behavior interventions are warranted to consolidate long-term benefits.