The relative importance of different dietary causes of obesity remains controversial. This review examines whether consumption of high-glycemic index (GI) carbohydrates may be a contributing factor. Although data from long-term studies are lacking, short-term investigations indicate that consumption of high-GI carbohydrates may increase hunger and promote overeating relative to consumption of items with a lower GI. As long-term research on GI and weight regulation accumulates, consumption of whole grain and lower GI cereals instead of highly refined cereals is a dietary change that may help prevent overeating and is consistent with current dietary guidelines.