Effect of a high-carbohydrate vs a high-cis-monounsaturated fat diet on lipid and lipoproteins in individuals with and without type 2 diabetes

It is not known whether the extent of the improvement in lipids and lipoproteins on a high-cis-monounsaturated (high-mono) diet compared with a high-carbohydrate (high-carb) diet is different in patients with type 2 diabetes mellitus (T2DM) and nondiabetic subjects. The aim of this study is to compare the effect of a high-mono and a high-carb diet on lipids and lipoproteins in patients with T2DM and nondiabetic subjects. Ten healthy nondiabetic men, 8 men with T2DM on dietary therapy alone, and 10 men with T2DM requiring insulin therapy were fed an isoenergic high-carb diet (60% energy as carbohydrate and 25% as fat) and a high-mono diet (50% energy as fat and 35% as carbohydrate) for 2 to 4 weeks in a randomized, crossover fashion. Dietary fiber, simple carbohydrates, and cholesterol were held constant across diets. The lipid and lipoprotein responses to these diets were compared in nondiabetic and T2DM subjects by repeated measures analysis of variance model. Patients with T2DM had 2.2 to 2.3 times greater reductions in plasma triacylglycerol, very low-density lipoprotein (VLDL) cholesterol, and total cholesterol/high-density lipoprotein cholesterol ratio (TC/HDLC) on the high-mono diet compared with the high-carb diet than the nondiabetic subjects (P =. 02-.04). The reductions in triacylglycerol and VLDL cholesterol were 2.7 times greater (P =. 009-.02) in T2DM subjects with high plasma triacylglycerol concentrations (>2.26 mmol/L) but only 1.4 to 2.0 times greater (P =. 16-.52) in T2DM patients with low triacylglycerol concentrations (<2.26 mmol/L) compared with nondiabetic subjects who all had low triacylglycerol concentrations (<2.26 mmol/L). Patients with T2DM experienced greater decreases in plasma triacylglycerol, VLDL cholesterol, and TC/HDLC on a high-mono diet compared with a high-carb diet than nondiabetic subjects. The extents of the improvements were likely related to plasma triacylglycerol concentrations in patients with T2DM.