Effects of a 4-week 70% high carbohydrate/15% low fat diet on glucose tolerance and on lipid profiles☆

Abstract 

In order to investigate the effect of high carbohydrate/low fat diet on glucose tolerance and on lipid profiles, we performed a 4-week crossover study. Japanese subjects (30 patients with type 2 diabetes mellitus, 15 subjects with impaired glucose tolerance and 8 subjects with normal glucose tolerance) were allocated either 55% standard carbohydrate/30% fat (sc) or 70% high carbohydrate/15% low fat (hc) diet for four weeks, and evaluated by OGTT and various parameters. Then, the diet was crossed over to another diet, and identical parameters were re-evaluated after four weeks. Area under the glucose concentration-time curve (AUG) or triglyceride did not show significant changes between the two diets. HDL–Cholesterol and body mass index decreased significantly by hc diet. Free fatty acids and homeostasis model assessment insulin resistance index showed a tendency to be decreased by hc diet. AUG hc/sc ratio was inversely correlated with AUG or free fatty acids on standard carbohydrate diet. In conclusion, the present 4-week high carbohydrate/low fat diet may be useful to reduce body weight and insulin resistance. The 4-week high carbohydrate/low fat diet did not affect glucose tolerance as a whole. Although the 4-week high carbohydrate/low fat diet decreased HDL–Chol, it did not increase triglyceride.

Keywords: High carbohydrate/low fat diet, Glucose tolerance, HDL–Cholesterol, Triglyceride, Free fatty acids, BMI