Effects of varying carbohydrate content of diet in patients with non-insulin-dependent diabetes mellitus

OBJECTIVE: To study effects of variation in carbohydrate content of diet on glycemia and plasma lipoproteins in patients with non-insulin-dependent diabetes mellitus (NIDDM). DESIGN: A four-center randomized crossover trial. SETTING: Outpatient and inpatient evaluation in metabolic units. PATIENTS: Forty-two NIDDM patients receiving glipizide therapy. INTERVENTIONS: A high-carbohydrate diet containing 55% of the total energy as carbohydrates and 30% as fats was compared with a high-monounsaturated-fat diet containing 40% carbohydrates and 45% fats. The amounts of saturated fats, polyunsaturated fats, cholesterol, sucrose, and protein were similar. The study diets, prepared in metabolic kitchens, were provided as the sole nutrients to subjects for 6 weeks each. To assess longer-term effects, a subgroup of 21 patients continued the diet they received second for an additional 8 weeks. MAIN OUTCOME MEASURES: Fasting plasma glucose, insulin, lipoproteins, and glycosylated hemoglobin concentrations. Twenty-four-hour profiles of glucose, insulin, and triglyceride levels. RESULTS: The site of study as well as the diet order did not affect the results. Compared with the high-monounsaturated-fat diet, the high-carbohydrate diet increased fasting plasma triglyceride levels and very low-density lipoprotein cholesterol levels by 24% (P < .0001) and 23% (P = .0001), respectively, and increased daylong plasma triglyceride, glucose, and insulin values by 10% (P = .03), 12% (P