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

Introduction: The worldwide prevalence of type 2 diabetes mellitus (T2DM) is increasing with most individuals being overweight or obese. Weight loss can reduce disease-related morbidity and mortality, and weight losses of 10-15Kg have been shown to reverse T2DM. This review aimed to determine the effectiveness of community-based educational interventions for weight loss in T2DM. Methods: Systematic review and meta-analysis of randomised controlled trials in obese or overweight adults, 18-75 years with a diagnosis of T2DM. Primary outcomes: weight and/or BMI. CINAHL, Medline, Embase, Scopus and Cochrane central register of controlled trials were searched from inception to June 2019. Trials were classified into specified a priori comparisons according to intervention type. A pooled standardised mean difference (from baseline to follow-up) and 95% confidence interval between trial groups (difference-in-difference) was 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: 7,383 records were screened; 228 full text articles were assessed from which, 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 T2DM