Educational weight loss interventions in obese and overweight adults with type 2 diabetes: a systematic review and meta‐analysis of randomized controlled trials

AIM: The worldwide prevalence of type 2 diabetes mellitus is increasing, with most individuals with the disease being overweight or obese. Weight loss can reduce disease‐related morbidity and mortality and weight losses of 10–15 kg have been shown to reverse type 2 diabetes. This review aimed to determine the effectiveness of community‐based educational interventions for weight loss in type 2 diabetes. METHODS: This is a systematic review and meta‐analysis of randomized controlled trials (RCT) in obese or overweight adults, aged 18–75 years, with a diagnosis of type 2 diabetes. Primary outcomes were weight and/or BMI. CINAHL, MEDLINE, Embase, Scopus and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched from inception to June 2019. Trials were classified into specified a priori comparisons according to intervention type. A pooled standardized mean difference (SMD) (from baseline to follow‐up) and 95% confidence intervals (95% CI) between trial groups (difference‐in‐difference) were estimated through random‐effects meta‐analyses using the inverse variance method. Heterogeneity was quantified using I (2) and publication bias was explored visually using funnel plots. RESULTS: Some 7383 records were screened; 228 full‐text articles were assessed and 49 RCTs (n = 12 461 participants) were included in this review, with 44 being suitable for inclusion into the meta‐analysis. Pooled estimates of education combined with low‐calorie, low‐carbohydrate meal replacements (SMD = –2.48, 95% CI –3.59, –1.49, I (2) = 98%) or diets (SMD = –1.25, 95% CI –2.11, –0.39, I (2) = 95%) or low‐fat meal replacements (SMD = –1.15, 95%CI –2.05, –1.09, I (2) = 85%) appeared most effective. CONCLUSION: Low‐calorie, low‐carbohydrate meal replacements or diets combined with education appear the most promising interventions to achieve the largest weight and BMI reductions in people with type 2 diabetes.