Glycemic Index, Body Weight and Health

January 20, 2009 updated by: University of Copenhagen
The purpose of this study is to investigate the effect of a diet with either high or low glycemic index (GI) on ad libitum (free) food intake, body weight, fat mass and fat-free mass, risk markers for diabetes and cardiovascular diseases, energy expenditure and substrate oxidation after 10 weeks´ intake in slightly overweight subjects.

Study Overview

Status

Completed

Conditions

Detailed Description

Experimental design Two matched groups are given high-GI or low-GI foods to their own diet throughout 10 weeks in a parallel design. A number of measurements are done before, during and at the end of the 10 weeks' intervention.

Subjects A total of 50 slightly overweight (body mass index, BMI = 25-30 kg/m2) women, 20-40 years of age participate. Subjects are randomized according to body weight, composition, age, sex and physical activity level into two matched groups.

A representative subgroup of 15 subjects is randomized from each diet group (a total of 30 subjects) for measurements of energy expenditure and substrate oxidation by ventilated hood as well as postprandial blood sampling.

Experimental diets Subjects eat their own diet until the intervention starts and perform a 7-day weighed dietary record for determination of habitual food intake. At the beginning and every 2 weeks during the 10 weeks' intervention all subjects are instructed in consuming a low-fat (<30 E%), high-carbohydrate diet (>55 E%) by a dietician. Subjects are each week given an amount of carbohydrate-rich foods with either high or low GI with instructions to consume a minimum amount of these every day. We aim at controlling about 75% of the subjects' total carbohydrate intake. The exact amount of test foods eaten is noted every day by the subjects by use of a diary and a diet scale. Instructions in food intake and cooking recipes are given by the dietician. A positive list and a negative list of food items is provided for each study group.

Besides the fixed minimum amount of experimental foods subjects can eat at liberty. Another 7-d dietary record is performed at week 5 and week 10 to register ad libitum food intake. To further validate the dietary records 24-h urine samples are taken during the registrations. Lithium will also be added to the experimental foods in week 4-5 to follow compliance during the study.

Measurements

All subjects:

Week 0, 2, 4, 6, 8, 10 we measured body weight,fat mass and fat-free mass using bio-electrical impedance.In week 0 and 10 we measured body composition by DEXA-scan, W/H-ratio and sagittal height. Blood samples fasting in week 0 and 10 (Glucose, insulin, triacylglycerol (TAG), non-esterified fatty acids (NEFA), leptin, T-cholesterol, LDL-chol, HDL-chol, fructosamine, glycated hemoglobin, GIP, GLP-1, GLP-2, ghrelin, factor VIIc, factor VIIb, PAI-1, Apo A IV.). Blood pressure in week 0 and 10 (fasting systolic and diastolic BP and heart rate). 24-h urine sample is collected in week 0, 5 and 10. Feces is collected in the subgroup in week 0 and 10.

Subgroup:

Week 10: Ventilated hood for measurement of fasting and 4-h postprandial energy expenditure and substrate oxidation. Postprandial appetite scores for hunger, satiety, fullness, prospective consumption, desire for something sweet, fatty. Postprandial blood samples for 4 hours after breakfast (30, 60, 90, 120, 180, 240 min): Glucose, insulin, NEFA, TAG, leptin, glucagon, GIP, GLP-1, GLP-2, ghrelin, paracetamol. At 240 min: factor VIIbt, PAI-1, Apo A IV.

Study Type

Interventional

Enrollment

43

Phase

  • Not Applicable

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

20 years to 41 years (Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

Female

Description

Inclusion Criteria:

  • healthy, slightly overweight (body mass index, BMI = 25-30 kg/m2) women, premenopausal, non-alcoholic (< 14 units alcohol/w)

Exclusion Criteria:

  • smoking, elite athletes, food allergies, pregnant, lactating, on medication, blood donation 3 months before, during and 3 months after the completion of the study

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Body weight
Fat mass and fat-free mass
Food intake

Secondary Outcome Measures

Outcome Measure
Appetite
Energy expenditure and substrate oxidation
Risk markers for diabetes and CVD

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Arne Astrup, Prof, Department of Human Nutrition, Centre for Advanced Food Studies, The Royal Veterinary and Agricultural University, Denmark

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

March 1, 2002

Study Completion

July 1, 2002

Study Registration Dates

First Submitted

May 9, 2006

First Submitted That Met QC Criteria

May 9, 2006

First Posted (Estimate)

May 10, 2006

Study Record Updates

Last Update Posted (Estimate)

January 21, 2009

Last Update Submitted That Met QC Criteria

January 20, 2009

Last Verified

February 1, 2002

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • (KF) 01-249/01
  • B184

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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