A Comparison of the Influence of a High-fat Diet Enriched in Monounsaturated Fatty Acids and Conventional Diet on Weight Loss and Metabolic Parameters in Obese Non-diabetic and Type 2 Diabetic Patients

Aims: The aim of our study was to compare the influence of a hypocaloric, high-fat diet enriched with MUFA (M) and conventional diet (C) on weight loss and metabolic parameters in obese non-diabetic and obese Type 2 diabetic subjects over a 3-month period. It was our hypothesis that the enriched diet would be more effective in decreasing blood glucose and glycated haemoglobin (HbA(1c)) than the control diet.

Methods: Twenty-seven Type 2 diabetic patients (54.5 +/- 3.5 years; DM), treated with diet or oral glucose-lowering agents, and 31 obese non-diabetic subjects (53.6 +/- 3.5 years; OB) were randomized to M or C. Individual calculations of energy requirements were based on the formula: [resting energy expenditure (REE) x 1.5] - 600 kcal. Subjects were assessed by a dietitian every 2 weeks and by a physician every month. Statistical analyses were carried out between the four groups--DM/M, DM/C, OB/M and OB/C--using pair Student's test and anova.

Results: After 3 months, body weight, waist-hip ratio, total body fat, levels of C-peptide, triglycerides and homeostasis model assessment (HOMA) decreased in all four groups (P < 0.01). However, fasting blood glucose and HbA(1c) decreased (P < 0.01) and high-density lipoprotein cholesterol increased significantly only in the DM/M group (P < 0.05). In general, M was well tolerated.

Conclusions: Individualized M and C diets were successful in improving metabolic and anthropometric parameters in both the obese non-diabetic and the Type 2 diabetic subjects. Although the superiority of the higher fat diet did not reach statistical significance, the decline in blood glucose and HbA(1c) in the Type 2 diabetic group on M was encouraging.