RMSEA = 0.048). The findings identified a direct negative relationship between the ego climate and the task climate. Furthermore, an inverse relationship was found between the task climate and body mass index, and a direct relationship was found between the ego climate and body mass index. Meanwhile, Mediterranean diet adherence was directly related to the task climate and negatively related to the ego climate. The main conclusions of the present study highlight the positive effects of a task-oriented motivational climate and adherence to a Mediterranean diet, with regards to body mass index. Furthermore, a task-oriented motivational climate and a lower body mass index are related to a more positive self-concept.