The association of self-efficacy and coping strategies with body mass index is mediated by eating behaviors and dietary intake among young females: A structural-equation modeling approach

Globally, around three billion people are either under- or overweight. Speculating the different roles of psychological factors in body weight between over- and underweight people, it was first hypothesized that whether or not the effects of self-efficacy and coping strategies on body mass index (BMI) is different between these two groups. We secondly predicted that their association is mediated by nutritional factors. Therefore, the present cross-sectional study was conducted to model the impact of self-efficacy and coping strategies on eating behaviors, dietary intake and BMI, using structural equation modeling in two BMI groups: low-to-normal-BMI (LBMI: BMI<21.75 kg/m(2)) and normal-to-high-BMI (HBMI: 21.75 kg/m(2) ≤ BMI). Female participants (N = 250, aged ≥18) were included using convenience sampling method and data of self-efficacy, coping strategies, eating behaviors and dietary intake were collected via questionnaires. The model fit was evaluated and confirmed by fit indices. The analysis revealed in both groups the participants tended to adopt emotion-focused coping strategy (EFCS) more than problem-focused coping strategy (PFCS) (mean score: 61.82 (7.96) vs 49.21 (6.73)). The HBMI group tended to use EFCS more than the LBMI group (P<0.001). In the LBMI group, self-efficacy, PFCS and EFCS had positive effects on BMI. Only the direct effect of self-efficacy (β = 0.314, P<0.001) and the indirect effects of PFCS and EFCS (through increasing unhealthy eating behaviors; β = 0.127, P<0.01, β = 0.095, P<0.05, respectively) were significant. In the HBMI group, self-efficacy had negative effect on BMI (both directly (β = -0.229, P<0.05) and indirectly (β = -0.103, P<0.05) by decreasing unhealthy eating behaviors). PFCS had no effect and EFCS had an indirect, positive effect on BMI (through increasing unhealthy eating behaviors, β = 0.162, P = 0.001). In conclusion, these findings suggest that improving self-efficacy and coping-strategies seems helpful to have a healthy BMI in both BMI groups and further interventions to reduce EFCS should be limited to overweight people.