A Low Glycemic Index Diet Combined with an Aerobic-Resistance Exercise Program Reduces Risk Factors Associated with the Metabolic Syndrome

Abstract

Background: The purpose of this study was to examine the effects of Low Glycemic Index (LGI) and High Glycemic Index (HGI) versions of a low fat, Moderate Carbohydrate (CHO), moderate protein diet, when combined with an exercise program, on Cardiovascular Disease (CVD) risk factors in people with Metabolic Syndrome (MetS). Methods: The four groups included ad libitum and 30% calorie restricted high and low GI diets. Twenty six individuals completed the 12 week intervention. Data was collected prospectively at weekly counselling sessions. Results: Calorie restriction was similar between groups (p=0.543), and thus the groups were pooled, leaving only the HGI and LGI groups. The LGI group significantly reduced the GI of their diet (10.5 GI units), significantly reduced the number of subjects classified with MetS (8 people), and had significantly greater improvements in total body weight (7.2 kg), BMI (2.0 kg/m2), percent body fat (3.3 %) and hip circumference (4.9 cm) compared to the HGI groups, as well as additional improvements in waist circumference (6.3 cm), blood pressure (10.5 mmHg systolic, 5.5 mmHg diastolic), triglycerides (0.6 mmol/L). Both groups had similar improvements in fitness. There were no significant changes in fasting levels of blood glucose, serum insulin, and serum total, HDL, or LDL cholesterol. Conclusions: The LGI diet and exercise program had a greater ability to reduce the number and severity of CVD risk factors in individuals with MetS, and represents valuable knowledge from which future lifestyle interventions can be developed to reduce the incidence of MetS and the development of CVD.