Previous reports have demonstrated that noninsulin-dependent diabetes mellitus often is associated with hypertriglyceridemia linked to hyperinsulinemia and enhanced cholesterogenesis. Studies with single meals have indicated that rice as compared to potato results in a less pronounced blood glucose and insulin response. These findings initiated the current study in which eight middle-aged patients with adult-onset, noninsulin-dependent diabetes were fed a standardized diet with potato or rice as the major carbohydrate source. Blood glucose control was the same during both dietary periods. When rice was the major carbohydrate source the very low density lipoprotein triglycerides decreased in six patients and the formation of bile acid, especially that of cholic acid, showed a significant drop. The results further underline a link between lipoprotein and bile acid metabolism.