Abstract
Background/Objectives: Data indicate that a low-glycemic index diet may be an effective nutritional approach to improve cardiometabolic parameters and support weight loss in obese individuals. The purpose of the study was to evaluate and compare the effects of a free-choice low-GI diet and a low-energy diet in women with excessive body weight on the value of anthropometric parameters, selected indices of lipid, carbohydrate, and fat tissue metabolism, and alterations in resting metabolic rate (RMR). Methods: Forty-six women were randomly assigned to either a low-GI diet (LGI) or a low-energy diet (LED) for 12 weeks. Dietary habits and anthropometric parameters (waist circumference, body weight, fat mass, total body water, and fat-free mass) were monitored and reviewed regularly. Biochemical parameters-including lipid profile, markers of glucose metabolism, adiponectin, leptin, glucagon-like peptide-1 (GLP-1), and RMR-were assessed at baseline and after three months of dietary intervention. Results: Both diets had a beneficial effect on monitored parameters; however, the LGI diet was shown to be superior in reducing waist circumference, LDL, non-HDL cholesterol, leptin, and HbA1c, and in increasing GLP-1 levels without decline in RMR. Conclusions: A low-GI diet, under dietary supervision, can improve metabolic performance and promote weight reduction in people with obesity.