The effect of weight reduction interventions for persons with type 2 diabetes: a meta-analysis from a self-regulation perspective.

Purpose: The main purpose of this article was to investigate the value of a self-regulation approach for weight reduction interventions in patients with type 2 diabetes. In addition, the potentially moderating effect of other intervention characteristics was explored.

Methods: In a meta-analysis of 34 studies, overall effect sizes were calculated for weight and A1C. The focus of the analysis was, however, on the moderating effect of intervention characteristics, especially whether interventions that score high on self-regulation produce stronger effects.

Results: The overall effect sizes (d) for weight loss in the short term (<6 months) were low and even lower in the longer term (>6 months). The overall effect sizes for A1C outcomes were higher and remained stable in the longer term. Interventions that scored high on self-regulation characteristics produced significantly better effects on both weight and A1C outcomes. Furthermore, "goal reformulation" increased the effect on weight outcomes whereas "emotion regulation" increased the effect on A1C. With respect to the other intervention characteristics, only the "inclusion of a patient's partner or relative" increased the effect on weight loss.

Conclusions: This meta-analysis underlines the importance of a self-regulation approach for weight reduction interventions in diabetes patients, in particular, for A1C outcomes. However, more research is needed to fully understand the relationship among self-regulation, weight, and A1C.