INSULIN SENSITIVITY AND LIPID-LEVELS IN OBESE SUBJECTS AFTER SLIMMINGDIETS WITH DIFFERENT COMPLEX AND SIMPLE CARBOHYDRATE CONTENT

The ideal hypocaloric diet should reduce body weight, decrease fat mor e than muscle tissue, and ameliorate insulin sensitivity and lipid lev els. The aim of this study was to investigate the effect of three hypo caloric diets with different carbohydrate (CHO) and fat contents on bo dy weight reduction, insulin release and sensitivity, and lipid levels in patients with simple obesity. Twenty-five obese subjects with norm al glucose tolerance were randomly allocated to three hypocaloric (800 kcal) diets containing: 60% high complex/high starch and fibre (HC/HS F-CHO) and 20% fat (group 1;11 subjects); 60% high simple/high natural fibre (HS/HNF-CHO) and 20% fat (group 2; 7 subjects); or 20% CHO (L-C HO) and 60% fat (group 3; 7 subjects). The remaining 20% of the diet w as protein. In all cases the duration of the diet was 21 days. Before and after the diet, seven subjects from each group underwent a hypergl ycemic clamp, and the other four subjects of group 1 underwent a eugly cemic-hyperinsulinemic clamp, combined with a glucose turnover study. A similar decrease in body weight, fat-free mass, fat mass, total chol esterol, LDL cholesterol and apo B levels was observed in the three gr oups. The M/I ratio during hyperglycemic and euglycemic-hyperinsulinem ic clamp and the glucose turnover rate during euglycemic-hyperinsuline mic clamp significantly decreased, and FFA levels significantly increa sed only after the HC/HSF-CHO diet. HDL cholesterol and apo A1 signifi cantly increased only during the HS/HNF-CHO diet. In conclusion, all h ypocaloric diets with different CHO and fat contents can decrease body weight, total cholesterol, LDL cholesterol, and apo B levels; a hypoc aloric diet with a HC/HSF-CHO content induces a state of insulin resis tance probably mediated by the increased FFA levels; and a hypocaloric diet with HS/HNF-CHO content does not worsen insulin sensitivity, and increases cholesterol and apo A1 levels.