The link between depression, eating behaviors and body mass index

Obesity and its psychosocial correlates represent an increasing public health concern. Prior international evidence suggests links between depression, anxiety, BMI, and eating behavior traits, yet these relationships remain understudied in Latin American populations. To address this gap, the present study examined associations among depression, anxiety, BMI, and specific eating behaviors, and explored whether eating behaviors mediate the relationship between mental health symptoms and BMI. Data were collected between 2023 and 2024 from 338 Argentine adults (18-67 years, M = 30.8, SD = 12.7; 68.9% women) through an online survey assessing height, weight, clinical information, anxiety (STAI-Trait), depression (BDI-II), and eating behaviors (AEBQ). In the regression model, BMI was positively associated with depression (β = 0.225, p < 0.001) and emotional overeating (β = 0.176, p = 0.002), and negatively associated with emotional undereating (β = -0.116, p = 0.046). Anxiety did not emerge as a significant predictor of BMI, despite being included in the analytical model. Mediation analyses indicated that emotional overeating partially mediated the association between depression and BMI (indirect estimate = 0.026, Z = 2.37, p = 0.018, 95% CI [0.006, 0.047]). Emotional undereating showed an opposite indirect pattern (indirect estimate = -0.024, Z = -2.15, p = 0.032, 95% CI [-0.046, -0.003]). Participants with obesity reported higher depression and emotional overeating, and lower under-eating and satiety responsiveness (F > 5.54, p < 0.019). We identified two pathways linking mental health, eating behaviors, and BMI: emotional overeating mediating the association between depressive symptoms and higher BMI, and emotional undereating mediating the association between depression and lower BMI. These findings highlight emotional eating as a relevant therapeutic target; psychosocial approaches such as cognitive-behavioral therapy, mindfulness-based interventions, or acceptance-based strategies may help address maladaptive eating patterns in weight-related care.