Efficacy of lifestyle weight loss interventions on regression to normoglycemia and progression to type 2 diabetes in individuals with prediabetes: a systematic review and pairwise and dose-response meta-analyses

Current recommendations for weight loss in individuals with prediabetes come from individual trials and are derived from older data. To elucidate the dose-dependent impacts of weight loss on participants with prediabetes to determine the optimal magnitude of weight loss required for the implementation of the most effective diabetes prevention program. We searched PubMed, Scopus, CENTRAL, CINAHL, and gray literature sources to September 2023 for randomized trials ≥6 mo that evaluated the efficacy of a lifestyle weight loss intervention on participants with prediabetes. We conducted random-effects pairwise meta-analyses to calculate relative and absolute effects. We performed a 1-stage weighted mixed-effects meta-analysis to elucidate the dose-response curves. Forty-four randomized trials with 14,742 participants with prediabetes [intervention duration range: 6–72 mo (median: 24 mo), mean weight loss range: 1%–9%] were included. Lifestyle weight loss interventions increased regression to normoglycemia by 11/100 participants (95% confidence interval [CI]: 8 more, 17 more; risk ratio: 1.51; 95% CI: 1.27, 1.80; n = 20 trials, grading of recommendations assessment, development, and evaluation = moderate], and reduced progression to type 2 diabetes by 8/100 participants (95% CI: 11 fewer, 6 fewer; risk ratio: 0.59; 95% CI: 0.51, 0.67; n = 37, grading of recommendations assessment, development, and evaluation = moderate). There were no significant or credible differences between subgroups categorized by the type and duration of intervention. Dose-response meta-analyses indicated that the risk of regression to normoglycemia increased, and the risk of progression to type 2 diabetes declined in a linear pattern within the range of weight loss from 1% to 9%. Over a median duration of 24 mo, with weight loss ranging from 1% to 9%, the relationship between weight loss and the progression to type 2 diabetes, as well as the regression to normoglycemia, follows a linear pattern. Any form of lifestyle weight loss intervention, including diet, exercise, or a combination of both, can have beneficial impacts on participants with prediabetes. This trial was registered at PROSPERO as CRD42023465322.