1. Introduction
T2DM, impaired fasting glucose
CARDIOVASCULAR DISEASE, IMPAIRED GLUCOSE TOLERANCE, INSULIN RESISTANCE, TYPE 2 DIABETES, TYPE 2 DIABETES MELLITUS, INSULIN SENSITIVITY, ENDOTHELIAL DYSFUNCTION
There is interest in the impact that dietary interventions can have on preventing the transition from insulin resistance to type 2 diabetes, including a suggestion that the bioactive components of cocoa may enhance fasting insulin sensitivity. However, a role for cocoa flavanols (CF) in reducing insulin resistance in the insulin-stimulated state, an important risk factor for cardiovascular disease, is unresolved. This study investigated whether CF consumption improved whole-body insulin-mediated glucose uptake (‘M’) in females with overweight/obesity, using a randomized, double-blinded, placebo-controlled, parallel-group design. Thirty-two premenopausal females (19–49 years; 27–35 kg·mIt is well established that overweight and obesity are risk factors for developing type 2 diabetes mellitus (T2DM). The progression from normal glucose regulation to T2DM usually involves the development of insulin resistance (IR), which in turn leads to impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT). There is interest in the impact that dietary interventions can have on preventing this transition, including awareness that some dietary phytochemicals may improve insulin sensitivity and thus reduce the risk of progression to T2DM [In addition to this link between IR and T2DM, the pathologies of endothelial dysfunction and IR appear to co-exist, with both being risk factors in the development of cardiovascular disease [Despite the paucity of primary data, multiple literature reviews have proposed a benefit of cocoa-containing foods in ameliorating ‘insulin resistance’ in humans, largely based on fasting, surrogate measures. Moreover, many protocols that have demonstrated a positive impact of cocoa-containing foods on measures of fasting insulin sensitivity have an initial run-in period where participants consume a diet that is low in flavonoids, which is maintained throughout any supplementation period, such that the intervention is on top of, and is compared to, a low-flavonoid background diet [