Recruiting

Ketogenic Diet

Sponsor:

University of Alabama at Birmingham

Code:

NCT06736028

Conditions

Obesity

Eligibility Criteria

Sex: All

Age: 18 - 65

Healthy Volunteers: Not accepted

Interventions

Diet Therapy

Calorie Restriction

Behavioral Support

Diet Therapy

Study Details

Brief summary:

The goal of this clinical trial is to investigate whether a Ketogenic Diet (KD) can increase Total Energy Expenditure (TEE), while benefiting appetite, during weight loss maintenance in reduced-obese individuals.

Conditions

Obesity

Study ID

NCT06736028

Start date

Aug 1, 2025

Status verified date

Apr, 2026

Completion date

Mar 30, 2027

Anticipated

Primary completion date

Dec 31, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 65

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • BMI 30-45 kg/m2
  • Both men and women
  • Age between 18-65 years
  • Sedentary to moderately active (<2 h/wk of moderate, structured, intentional, exercise)

Exclusion Criteria:

  • Pregnancy or lactation
  • Daily use of tobacco (>1 pk/wk)
  • Change in weight greater than 5 lb in the previous 3 months
  • Cognitive impairment
  • Previous bariatric surgery
  • History of eating disorder
  • Presence of any condition (e.g. DM2, PCOS, inflammatory disease, untreated thyroid disease, fluid overload states such as chronic kidney disease, congestive heart failure, or cirrhosis)
  • Use of any medication (e.g., glucocorticoid, GLP-1 analogues, hormone replacement therapy) deemed to interfere with study outcomes.
  • Pre-menopausal women will need to have a regular menstrual cycle (28+/-2 days) or be on hormonal contraceptives
  • Fasting glucose plasma concentration >125 mg/dl and/or HbA1c > 6.4%

Study Design

Enrollment

20 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Ketogenic Diet

Participants randomized to the ketogenic diet will follow a diet with 5% energy from carbohydrates, 70% from fat, and 25% from protein for 6 weeks. The first 2 of the 6 weeks weeks will be a gradual refeeding, with participants slowly withdrawing from the meal replacements used during the 4-week weight loss phase, while introducing more food.

active comparator: Low-Fat Diet

Participants randomized to the low-fat diet will follow a diet with 50% energy from carbohydrates, 25% energy from fat, and 25% energy from protein for 6 weeks. The first 2 of the 6 weeks weeks will be a gradual refeeding, with participants slowly withdrawing from the meal replacements used during the 4-week weight loss phase, while introducing more food.

Interventions

Diet Therapy

Participants will be provided food to meet the ketogenic diet prescription for the 6-week weight maintenance phase.

Calorie Restriction

Participants will follow a commercial low-energy diet and be provided with meal replacements for 4 weeks aiming to achieve a minimum of 5% weight loss.

Behavioral Support

Participants will meet weekly with a registered dietitian, for a 20-minute consultation throughout the entire study period (10 weeks) to increase engagement and improve adherence and retention.

Diet Therapy

Participants will have food provided to meet the standard low-fat diet prescription for the 6-week weight maintenance phase.

Primary outcome measure

  • Change from baseline total energy expenditure [ Time Frame: Baseline, week 6, week 10 ]

Central Contacts and Locations

Central contacts

Catia Martins, PhD

205-934-7922catia197@uab.edu

Locations

University of Alabama at Birmingham

Recruiting

Birmingham, Alabama, United States, 35294

Contacts

Catia Martins, PhD

2059347922catia197@uab.edu

More Information

Sponsor

University of Alabama at Birmingham

Last update posted

Apr 7, 2026

Last verified

Apr, 2026

Keywords

  • Ketogenic Diet
  • Weight loss
  • Weight loss maintenance
  • Appetite
  • Energy expenditure

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by University of Alabama at Birmingham on 2026-04-07.