Effects of Calorie-Restricted Low-Carbohydrate Diet on Glucose and Lipid Metabolism in Otsuka Long Evans Tokushima Fatty Rats

Abstract

Aim: We investigated the effects of a calorie-restricted low-carbohydrate diet on glucose and lipid metabolism, and body fat distribution, especially on the secretion of leptin and lipoprotein lipase from adipose tissue in Otsuka Long Evans Tokushima Fatty (OLETF) rats.
Methods: Forty-three week-old male OLETF rats were randomized into three groups (n=6 per group): the HC group (HC) was fed a diet with 60% carbohydrate; the LC group (LC) with 30% carbohydrate; and the P-HC group (P-HC) with 60% carbohydrate and pioglitazone (0.1%). The total calorie intake was restricted to 70% of the average intake from each diet (60 kcal/day). The diets were continued for 8 weeks.
Results: Similar decreases in body weight and serum glucose were observed in the three groups. Serum insulin concentration was significantly decreased in LC and P-HC compared to HC. Serum total cholesterol and triglycerides decreased significantly (p<0.05) in LC and P-HC compared to HC. The decrease of visceral fat area measured by computed tomography was greatest in LC among the three groups. At the end of the diet, leptin secretion from visceral adipose tissue and lipoprotein lipase (LPL) activity in subcutaneous adipose tissue were significantly higher in LC and P-HC compared to HC (p<0.05).
Conclusion: These results indicate that under calorie-restricted conditions, low carbohydrates are much more effective than high carbohydrates in improving insulin sensitivity.