CClinicalTrials.gg
CompletedNCT03499509CHAMPIONUpdated May 18, 2025Results posted

Obesity Risk in African American Women is Determined by a Diet-by-phenotype Interaction

An interventional study of Low Glycemic Diet and High Glycemic Diet in Diet Modification, sponsored by University of Alabama at Birmingham. Completed at 1 site in United States. Open to female participants aged 19 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-05-18.

Sponsored by University of Alabama at Birmingham · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
67
Allocation
Randomized
Ages
19 Years to 65 Years
Sex
Female
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Study summary

The Scientific Premise of this study is that the high level of obesity displayed by African American (AA) women is due to the ability to secrete large amounts of insulin when sugary foods are consumed. When AA women eat a diet rich in starchy or sugary food (a "high-glycemic" diet that stimulates insulin secretion), the food that is eaten is stored as fat rather than being burned as fuel. The investigators previous research has suggested that AA women have an easier time losing weight and keeping it off when eating a low-glycemic diet. The proposed study will be the first randomized clinical trial to test the effect of high and low glycemic diets for weight loss and weight-loss-maintenance in obese AA women.

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Conditions studied

  • Diet Modification

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Who can participate

Ages eligible
19 Years to 65 Years
Sexes eligible
Female
Accepts healthy volunteers
Yes

Inclusion criteria

  • BMI 30-45 kg/m2
  • Sedentary to moderately active (\<2 hours/wk of moderate, structured, intentional exercise.
  • Normal menstrual cycle

Exclusion criteria

Exclusion Criteria:

  • History of eating disorder
  • daily use of tobacco (>1 pack/wk)
  • change in weight greater than 5 pounds in previous 3 months
  • presence of any condition (e.g. PCOS) or use of any medication (e.g. glucocorticoid) deemed by the project physician to interfere with study outcomes
  • applicants will be screened with a standard oral glucose tolerance test. If a participant's 2 hour glucose if >200, they will not be able to enroll in the study.
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Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
67 participants (actual)

Study arms

  • Experimental
    Low Glycemic Diet

    Low Glycemic (LG) diet: The LG diet was made up of foods that do not stimulate insulin secretion and was composed of 20% CHO, 55% fat, and 25% protein. The diet emphasized complex over simple carbohydrates and allowed dairy products, fruits, and vegetables within allowance of the diet.

    Other: Low Glycemic Diet

  • Placebo comparator
    High Glycemic Diet

    High Glycemic (HG) diet: The HG diet aligned with the United States Department of Agriculture (USDA) guidelines (http://health.gov/dietaryguidelines/2015/guidelines/) and was composed of 55% CHO, 20% fat, and 25% protein. The diet emphasized complex over simple carbohydrates and allowed dairy products, fruits, and vegetables within allowance of the diet.

    Other: High Glycemic Diet

Interventions

  • OtherLow Glycemic Diet

    Low Glycemic (LG) diet: The LG diet was made up of foods that do not stimulate insulin secretion and was composed of 20% CHO, 55% fat, and 25% protein. The diet emphasized complex over simple carbohydrates and allowed dairy products, fruits, and vegetables within allowance of the diet.

    Also known as: Low Carbohydrate Diet

  • OtherHigh Glycemic Diet

    High Glycemic (HG) diet: The HG diet aligned with the United States Department of Agriculture (USDA) guidelines (http://health.gov/dietaryguidelines/2015/guidelines/) and was composed of 55% CHO, 20% fat, and 25% protein. The diet emphasized complex over simple carbohydrates and allowed dairy products, fruits, and vegetables within allowance of the diet.

    Also known as: Low Fat Diet

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What researchers measure

Primary outcomes

  1. Total Energy Expenditure

    Total energy expenditure measured by doubly labeled water. The protocol is based on established procedures \[12\]. Urine samples are analyzed in duplicate for H218O and 2H2O enrichments using Thermo Scientific Delta V Advantage IRMS with GasBench. CO2 production rates are determined using a fixed assumption for the dilution space ratio (1.043), using Equation 3 of Speakman et al. \[10\], and energy expenditure is calculated with equation 5 of Speakman et al. \[10\]. \[10\] Speakman JR, Yamada Y, Sagayama H et al. A standard calculation methodology for human doubly labeled water studies. Cell Rep Med 2021; 2:100203. \[12\] Goran MI, Carpenter WH, McGloin A et al. Energy expenditure in children of lean and obese parents. American Journal of Physiology 1995; 31:E917-E924. \[13\] Wolfe RR. Measurement of Total Energy Expenditure Using the Doubly-Labeled Water Method. In: Radioactive and Stable Isotope Tracers in Biomedicine. Edited by: Wiley-Liss. 1992.

    Time frame: Baseline, Week 13

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Results

Posted May 18, 2025

Participant flow

Participant flow — Overall Study
MilestoneLow Glycemic DietHigh Glycemic Diet
Started3433
Completed2321
Not completed1112

Outcome measures

PrimaryTotal Energy Expenditure

Total energy expenditure measured by doubly labeled water. The protocol is based on established procedures \[12\]. Urine samples are analyzed in duplicate for H218O and 2H2O enrichments using Thermo Scientific Delta V Advantage IRMS with GasBench. CO2 production rates are determined using a fixed assumption for the dilution space ratio (1.043), using Equation 3 of Speakman et al. \[10\], and energy expenditure is calculated with equation 5 of Speakman et al. \[10\]. \[10\] Speakman JR, Yamada Y, Sagayama H et al. A standard calculation methodology for human doubly labeled water studies. Cell Rep Med 2021; 2:100203. \[12\] Goran MI, Carpenter WH, McGloin A et al. Energy expenditure in children of lean and obese parents. American Journal of Physiology 1995; 31:E917-E924. \[13\] Wolfe RR. Measurement of Total Energy Expenditure Using the Doubly-Labeled Water Method. In: Radioactive and Stable Isotope Tracers in Biomedicine. Edited by: Wiley-Liss. 1992.

Time frame:
Baseline, Week 13
Reported as:
Mean · kcal/day
Total Energy Expenditure
kcal/dayLow Glycemic DietHigh Glycemic Diet
Baseline2411 ± 3422316 ± 289
week 132318 ± 3622179 ± 413

Adverse events

Collected over 13 weeks. Non-serious events are listed at a 0% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
Low Glycemic Diet0/34 (0%)0/34 (0%)0/34 (0%)
High Glycemic Diet0/33 (0%)0/33 (0%)0/33 (0%)

Baseline characteristics

Age, Categorical
Age, Categorical(Participants)Low Glycemic DietHigh Glycemic DietTotal
<=18 years000
Between 18 and 65 years343367
>=65 years000
Sex: Female, Male
Sex: Female, Male(Participants)Low Glycemic DietHigh Glycemic DietTotal
Female343367
Male000
Race (NIH/OMB)
Race (NIH/OMB)(Participants)Low Glycemic DietHigh Glycemic DietTotal
American Indian or Alaska Native000
Asian000
Native Hawaiian or Other Pacific Islander000
Black or African American343367
White000
More than one race000
Unknown or Not Reported000
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Study locations

1 site
  • The University of Alabama at Birmingham
    Birmingham, Alabama 35294, United States
08

References and documents

Study documents

  • Protocol and statistical analysis plan · Jun 1, 2019

Documents are hosted by the registry — open the source record to download them.

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Registry details

Key details

Study ID
NCT03499509
Lead sponsor
University of Alabama at Birmingham
Collaborators
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Responsible party
Barbara Gower (Professor, University of Alabama at Birmingham) — Principal investigator
First posted
Apr 17, 2018
Start date
Mar 19, 2019
Primary completion
Apr 30, 2024
Completion
Apr 30, 2024
Results posted
May 18, 2025
Last update
May 18, 2025

Study contacts

Barbara Gower, PhD
principal investigator · The University of Alabama at Birmingham

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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