Trial Outcomes & Findings for Obesity Risk in African American Women is Determined by a Diet-by-phenotype Interaction (NCT NCT03499509)

NCT ID: NCT03499509

Last Updated: 2025-05-18

Results Overview

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.

• Recruitment status: COMPLETED
• Study phase: NA
• Target enrollment: 67 participants
• Primary outcome timeframe: Baseline, Week 13
• Results posted on: 2025-05-18

Participant Flow

Participant milestones

Measure	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.	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.
Overall Study STARTED	34	33
Overall Study COMPLETED	23	21
Overall Study NOT COMPLETED	11	12

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

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

Baseline characteristics by cohort

Measure	Low Glycemic Diet n=34 Participants 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.	High Glycemic Diet n=33 Participants 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.	Total n=67 Participants Total of all reporting groups
Age, Categorical <=18 years	0 Participants n=93 Participants	0 Participants n=4 Participants	0 Participants n=27 Participants
Age, Categorical Between 18 and 65 years	34 Participants n=93 Participants	33 Participants n=4 Participants	67 Participants n=27 Participants
Age, Categorical >=65 years	0 Participants n=93 Participants	0 Participants n=4 Participants	0 Participants n=27 Participants
Sex: Female, Male Female	34 Participants n=93 Participants	33 Participants n=4 Participants	67 Participants n=27 Participants
Sex: Female, Male Male	0 Participants n=93 Participants	0 Participants n=4 Participants	0 Participants n=27 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=93 Participants	0 Participants n=4 Participants	0 Participants n=27 Participants
Race (NIH/OMB) Asian	0 Participants n=93 Participants	0 Participants n=4 Participants	0 Participants n=27 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=93 Participants	0 Participants n=4 Participants	0 Participants n=27 Participants
Race (NIH/OMB) Black or African American	34 Participants n=93 Participants	33 Participants n=4 Participants	67 Participants n=27 Participants
Race (NIH/OMB) White	0 Participants n=93 Participants	0 Participants n=4 Participants	0 Participants n=27 Participants
Race (NIH/OMB) More than one race	0 Participants n=93 Participants	0 Participants n=4 Participants	0 Participants n=27 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=93 Participants	0 Participants n=4 Participants	0 Participants n=27 Participants

PRIMARY outcome

Timeframe: Baseline, Week 13

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.

Outcome measures

Measure	Low Glycemic Diet n=23 Participants 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.	High Glycemic Diet n=21 Participants 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.
Total Energy Expenditure Baseline	2411 kcal/day Standard Deviation 342	2316 kcal/day Standard Deviation 289
Total Energy Expenditure week 13	2318 kcal/day Standard Deviation 362	2179 kcal/day Standard Deviation 413

Adverse Events

Low Glycemic Diet

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

High Glycemic Diet

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Barbara Gower, PhD

The University of Alabama at Birmingham

Phone: 205-934-4087

Email: bgower@uab.edu

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place