Effects of A Low-Carbohydrate Diet and A Low-Fat Diet on Weight and Glycemic Control in Type 2 Diabetics Mellitus

Objective To compare the effects of a 1-year intervention with a low-carbohydrate and a low-fat diet on weight and glycemic control in patients with type 2 diabetes mellitus.Methods The randomized controlled clinical trial was taken to assign 90 overweight patients with type 2 diabetes mellitus to the low-carbohydrate diet (A) group and low-fat diet (B) group,with 45 patients in each.The patients in the group A were given a low-carbohydrate diet and biguanides;while those in the group B were given a low-fat diet and biguanides.The body weight,glycosylated hemoglobin (HbA1c),blood pressure and lipids were detected before treatment and 3,6,and 12 months after the treatment.Results Before and after the treatment there were statistical differences in body weight and high density lipoprotein Cholesterol (HDL-C) between the two groups (P0.01);but no statistically significant difference was found in blood pressure,serum total cholesterol (TC),low density lipoprotein Cholesterol (LDL-C),serum triglyceride (TG) and HbA1c (P0.05).The evident decreases of body weight and HbA1c of the patients in the two groups were mainly found at the first three months of treatment.The average decreases of body weight in group A and B were 1.8 kg/month and 1.0 kg/month respectively;and the decreases of HbA1c were both 0.6%.Nevertheless,the decreases of weight in one year in both group were 3.4 kg.Conclusion For overweight patients with type 2 diabetes,a low-carbohydrate diet a low-fat diet for one year have similar effects on HBAlc,and no significant effect on blood pressure.However the low-carbohydrate diet produces a greater decrease than the low-fat diet;and the latter can obviously increase LDL-C level.