Published evidence exploring the effects of dietary resistant starch (RS) on human cardiometabolic health is inconsistent. This review aimed to investigate the effect of dietary RS type 2 (RS2) supplementation on body weight, satiety ratings, fasting plasma glucose, glycated hemoglobin (HbA1c), insulin resistance and lipid levels in healthy individuals and those with overweight/obesity, the metabolic syndrome (MetS), prediabetes or type 2 diabetes mellitus (T2DM). Five electronic databases were searched for randomised controlled trials (RCTs) published in English between 1982-2018, with trials eligible for inclusion if they reported RCTs involving humans where at least one group consumed ≥8 grams of RS2 per day and measured body weight, satiety, glucose and/or lipid metabolic outcomes. Twenty-two RCTs involving 670 participants were included. Meta-analyses indicated that RS2 supplementation significantly reduced serum triacylglycerol concentrations (mean difference (MD) = -0.10 mmol/L; 95% CI -0.19, -0.01, P=0.03) in healthy individuals (n=269) and reduced body weight (MD = -1.29 kg; 95% CI -2.40, -0.17, P=0.02) in people with T2DM (n=90), however these outcomes were heavily influenced by positive results from a small number of individual studies which contradicted the conclusions of the majority of trials. RS2 had no effects on any other metabolic outcomes. All studies ranged from 1-12 weeks in duration, contained small sample sizes (10-60 participants) and most had an unclear risk of bias. Short-term RS2 supplementation in humans is of limited cardiometabolic benefit.
Matthew Snelson, Jessica Jong, Deanna Manolas, Smonda Kok, Audrey Louise, Romi Stern, Nicole J Kellow, Metabolic effects of resistant starch type 2: a systematic literature review and meta-analysis of randomised controlled trials, Nutrients, Volume 11, Issue 8, 2019, Page 1833