As the incidence and prevalence of diabetes increases, intervention through dietary education is becoming more important for diabetes control. This systematic review examines the evidence for the efficacy of dietary education interventions on diabetes control. The study subjects were patients with type 2 diabetes, and the main outcome variable was glycosylated hemoglobin level (HbA1c). The target studies were randomized controlled trials. Thirty-six studies were included in the analysis, of which 33 were included in the meta-analysis. The effect size between dietary education and general interventions was -0.42 (n = 5639, MD = -0.42; 95% CI -0.53 to -0.31) and was significantly different (Z = 7.73, p < 0.001). When subgroup analyses were performed following the application periods, intervention methods, and intervention contents, the mean differences in 4-6-month application, individual education, and diet-exercise-psychosocial intervention were -0.51, (n = 2742, 95% CI -0.71 to -0.32), -0.63 (n = 627, 95% CI -1.00 to -0.26), and -0.51 (n = 3244, 95% CI -0.71 to -0.32), respectively. Dietary education interventions provided for at least 3 months were highly effective in controlling HbA1c levels. Regarding the education method, individualized education was more effective, and contact or non-contact education may be applied for this. Combining diet, exercise, and psychosocial intervention is more effective than diet education alone.
Keywords: diabetes mellitus; diet; education; systematic review.