Effect of Glycemic Load on Body Composition

December 30, 2008 updated by: Universidad Autonoma de Baja California

Assessment of Glycemic Load on Body Composition Among Overweight and Obese Adults During 12 Month Period

The aim of this study is to compare the effects of diets with different glycemic load (GL) on body composition and biochemical markers in overweight and obese subjects during a 12-month period.

Study Overview

Status

Terminated

Conditions

Detailed Description

Study Procedure:

The study is a randomized, experimental, parallel design conducted in a group of Mexican subjects during a 6-month period. Anthropometric and biochemical data will be determined at 0, 3, 6, 9 and 12 months.

Subjects:

Overweight or obese adults were assigned into two groups: LGL diet and HGL diet. Subjects who were pregnant or had diabetes, cancer, psychiatric disorders or physical disabilities were excluded.

Diets and Dietary Assessment:

Two diets were designed including LGL and HGL diets. GI values of each food were estimated from the tables by Foster-Powell et al. Daily GL was determined by the product of total dietary carbohydrate (grams) and GI of each food and adjusted to energetic intake using the following formulas: GI = Σ (GI of each food X proportion of total carbohydrate contributed from each food); GL= Σ (GI of each food × grams of total carbohydrate from each food)/1000 kcal.

Diets were designed according to the food habits of Mexicans living in the Tijuana area. On the first day, subjects received different menus of either LGL or HGL diets, according to the randomization. A research assistant was available by mail or by phone for questions during the 6-month period. An e-mail, as a reminder and reinforcement to maintain the diet, was sent every 2 weeks to all participants. Subjects who completed the 3-day dietary record (two weekdays and one weekend day) were included in the analysis.

Anthropometric Measurements:

Height was measured to the nearest millimeter using a portable stadiometer (model 214 Road Rod, Seca Corp., Hanover, MD). Weight was measured to the nearest 0.1 kg using an electronic scale (Bod Pod, Life Measurement Inc., Concord, CA). Subjects were dressed in light clothing and were not wearing shoes. Body mass index (BMI) was calculated using the following formula: weight (kg)/height (m2). Waist circumference (WC) was measured at the minimum circumference between the iliac crest and the rib cage. Fat mass (in kg) and total body fat percentage were measured by plethysmography with the Bod Pod. The subjects entered the Bod Pod wearing a bodysuit and Lycra hat.

Blood Analysis:

Venous blood samples were taken at 8 AM from an antecubital vein after a 12-hour overnight fast, again at baseline and at 3 months after beginning the study. Blood samples were centrifuged at 3500 × g for 3 minutes, and plasma was removed and analyzed immediately after collection. For quantitative determination of glucose in serum, the glucose oxidase procedure based on a modified Trinder method was used (SERA-PAK Plus, Bayer, Sées, France). Serum insulin levels were determined by chemiluminescent immunoassay by the IMMULITE 2000 analyzer (Diagnostic Products Corporation, Los Angeles, CA). Homeostasis model assessment (HOMA) was used to estimate insulin resistance and was computed as follows: (fasting serum insulin [μU/ml] × fasting plasma glucose [mmol/L]/22.5). Total cholesterol, HDL-cholesterol and triglycerides were measured by enzymatic methods (SERA-PAK Plus); LDL-cholesterol was calculated using the Friedwald formula: LDL (mmol/L) = total cholesterol - (TG/2.2) - HDL.

Physical Activity Assessment:

A questionnaire containing seven questions from the International Physical Activity Questionnaire (IPAQ) was used to evaluate physical activity at baseline and at 1, 3 and 6 months after study initiation.

Statistical Analysis:

Mean ± standard deviations were calculated using descriptive statistics in all variables. Anthropometric measurements were evaluated, and it was determined that they did not meet the normality test (Kolmogorov-Smirnov and Shapiro-Wilk). To test differences between groups on biochemical and anthropometric measurements, Mann-Whitney non-parametric test for independent samples was performed. For comparison of differences before, at 3 and 6 months after intervention in the same treatment group, we used Friedman non-parametric test for repeated measurements. To test differences between groups on diet intake at baseline and at the end of the study, Mann-Whitney non-parametric test for independent samples was performed.

Study Type

Interventional

Enrollment (Actual)

29

Phase

  • Early Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Baja California
      • Tijuana, Baja California, Mexico, 22390
        • Facultad de Medicina y Psicología

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

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Overweight or obese adults

Exclusion Criteria:

  • Subjects who are pregnant or have diabetes, cancer, psychiatric disorders or physical disabilities

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: Supportive Care
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: A
This group will receive a low glycemic load
Low glycemic load diet
Other Names:
  • Low glycemic index
Active Comparator: B
This group will receive a high glycemic load
High glycemic load diet

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Reduction of body fat percentage
Time Frame: 3, 6, 9 and 12 months
3, 6, 9 and 12 months

Secondary Outcome Measures

Outcome Measure
Time Frame
Reduction of homeostasis model assessment (HOMA)
Time Frame: 3, 6, 9 and 12 months
3, 6, 9 and 12 months

Collaborators and Investigators

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

Investigators

  • Principal Investigator: Arturo Jimenez-Cruz, MD, Universidad Autonoma de Baja California

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

January 1, 2007

Primary Completion (Anticipated)

December 1, 2008

Study Completion (Anticipated)

December 1, 2008

Study Registration Dates

First Submitted

January 16, 2008

First Submitted That Met QC Criteria

January 28, 2008

First Posted (Estimate)

January 29, 2008

Study Record Updates

Last Update Posted (Estimate)

December 31, 2008

Last Update Submitted That Met QC Criteria

December 30, 2008

Last Verified

December 1, 2008

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • UABC4268
  • UABC20074268

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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