Glycemic Load, Weight Loss and Cardiovascular Disease Risk

To investigate the hypothesis that reducing the glycemic load of the diet will improve changes in body composition and cardio-vascular risk factors. The study compares a conventional reduced-fat, high carbohydrate diet with 3 means of reducing glycemic load: changing the carbohydrates to low-GI choices, replacing some of the carbohydrate with protein, or combining both effects to produce the lowest glycemic load.

Official Title

The Effect of 4 Diets Varying in Glycemic Index, Glycemic Load, Carbohydrate and Protein, on Weight, Body Composition and Cardio-Vascular Risk Factors

Conditions

Overweight/Obesity

Study Type

Interventional

Study Design

Treatment, Randomized, Open Label, Active Control, Parallel Assignment, Efficacy Study

Further Details

Primary Outcome Measures:

• weight loss at 12 weeks
• Fat loss at 12 weeks
• Lean mass change at 12 weeks

Secondary Outcome Measures:

• Total cholesterol, LDL and HDL cholesterol change at 12 weeks
• Glucose, insulin & measures of insulin sensitivity change at 12 weeks
• TG change at 12 weeks
• Leptin change at 12 weeks
• CRP change at 12 weeks

Conventional low fat diets produce modest wegiht loss at best and the results are not well maintained. More recently there has been interest in low glycemic index and high protien diets wiht some evidence that these produce better fat loss and improvement in cardiovascular risk factors. This trial aims to evaluate these different approaches and compare the outcomes over 12 weeks. Major outcomes are weigth loss, body composition change, blood lipids change, measures of glucose homeostasis, insulin resistance, leptin and CRP.

Study Start

March 2002; Study completion: October 2004

Eligibility & Criteria

• Ages Eligible for Study: 18 Years – 40 Years
• Genders Eligible for Study: Both
• Accepts Healthy Volunteers

Inclusion Criteria:

• 18-40 years of age
• BMI >=25
• Stable weight for 3 months
• Non-vegetarian
• Good understanding of English

Exclusion Criteria:

• Medications other than the contraceptive pill
• Weight >150kg (weight limit of DEXA machine)
• Vegetarian/specific diets (diets included red meat)
• Diabetes or impaired glucose tolerance
• Pregnancy

Total Enrolment

120

Contact Details

University of Sydney, Sydney, New South Wales, 2006, Australia

• Jennie C Brand-Miller, PhD, Principal Investigator, University of Sydney

Published Results