This article summarizes current findings regarding the use of low-glycemic index (GI) diets for weight loss and type 2 diabetes control. Results from cross-sectional studies evaluating the association between dietary GI and body mass index had equivocal results, especially when dietary fiber was included in the model. Of five prospective cohort studies, two reported increased risk of type 2 diabetes diagnosis with higher dietary GI or glycemic load (GL). Risk of type 2 diabetes appeared to have a stronger association with carbohydrate intake or GL than with GI. Evidence from intervention studies using a low-GI approach for weight loss produced inconsistent results, especially for longer-term studies. In intervention studies with type 2 diabetes patients, consumption of a low-GI diet resulted in lower hemoglobin A1c concentrations in participants of shorter-term studies. Recent evidence adds to the controversy regarding the effectiveness of consuming low-GI diets for glycemic control and weight reduction.