NCT06736028

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.

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
20

participants targeted

Target at below P25 for not_applicable obesity

Timeline
2mo left

Started Aug 2025

Shorter than P25 for not_applicable obesity

Geographic Reach
1 country

1 active site

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress84%
Aug 2025Jun 2026

First Submitted

Initial submission to the registry

December 10, 2024

Completed
6 days until next milestone

First Posted

Study publicly available on registry

December 16, 2024

Completed
8 months until next milestone

Study Start

First participant enrolled

August 1, 2025

Completed
11 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

June 30, 2026

Expected
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

June 30, 2026

Last Updated

December 18, 2025

Status Verified

December 1, 2025

Enrollment Period

11 months

First QC Date

December 10, 2024

Last Update Submit

December 17, 2025

Conditions

Keywords

Ketogenic DietWeight lossWeight loss maintenanceAppetiteEnergy expenditure

Outcome Measures

Primary Outcomes (1)

  • Change from baseline total energy expenditure

    Total Energy Expenditure (TEE) refers to the total amount of energy (calories) your body uses in a day. Twenty-four-hour EE and RQ will be measured inside the whole room indirect calorimeter (chamber) following standard procedures

    Baseline, week 6, week 10

Secondary Outcomes (16)

  • Change in appetite ratings

    Baseline, week 6, week 10

  • Change in total body composition

    Baseline, week 4, week 6, week 10

  • Change in total body composition

    Baseline, week 4, week 6, week10

  • Change in fasting insulin

    Baseline, week 6, week 10

  • Change in fasting cholecystokinin

    Baseline, week 6, week 10

  • +11 more secondary outcomes

Other Outcomes (8)

  • Blood work: beta hydroxybutyrate

    Week 1, week 2, week 3, week 4, week 5, week 6, week 7, week 8, week 9, week 10

  • Urine sample: acetoacetate

    Week 1, week 2, week 3, week 4, week 5, week 6, week 7, week 8, week 9, week 10

  • Change in glucose

    Baseline, week 6, week 10

  • +5 more other outcomes

Study Arms (2)

Ketogenic Diet

EXPERIMENTAL

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.

Behavioral: Diet TherapyBehavioral: Calorie RestrictionBehavioral: Behavioral Support

Low-Fat Diet

ACTIVE COMPARATOR

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.

Behavioral: Calorie RestrictionBehavioral: Behavioral SupportBehavioral: Diet Therapy

Interventions

Diet TherapyBEHAVIORAL

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

Ketogenic Diet

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.

Ketogenic DietLow-Fat Diet

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.

Ketogenic DietLow-Fat Diet

Eligibility Criteria

Age18 Years - 65 Years
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • 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)

You may not qualify if:

  • 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%

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

University of Alabama at Birmingham

Birmingham, Alabama, 35294, United States

RECRUITING

MeSH Terms

Conditions

ObesityWeight Loss

Interventions

Diet TherapyCaloric RestrictionBehavior Therapy

Condition Hierarchy (Ancestors)

OverweightOvernutritionNutrition DisordersNutritional and Metabolic DiseasesBody WeightSigns and SymptomsPathological Conditions, Signs and SymptomsBody Weight Changes

Intervention Hierarchy (Ancestors)

Nutrition TherapyTherapeuticsEnergy IntakeDietNutritional Physiological PhenomenaDiet, Food, and NutritionPhysiological PhenomenaPsychotherapyBehavioral Disciplines and Activities

Central Study Contacts

Catia Martins, PhD

CONTACT

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
NONE
Purpose
TREATMENT
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Associate Professor

Study Record Dates

First Submitted

December 10, 2024

First Posted

December 16, 2024

Study Start

August 1, 2025

Primary Completion (Estimated)

June 30, 2026

Study Completion (Estimated)

June 30, 2026

Last Updated

December 18, 2025

Record last verified: 2025-12

Data Sharing

IPD Sharing
Will share

This project will produce demographic information, anthropometric and body composition data, energy expenditure, fat oxidation, plasma concentrations of several gastrointestinal hormones involved in appetite regulation, insulin, glucose, blood lipids, and subjective appetite feelings. Data will be obtained from bioimpedance analysis and dual-energy x-ray absorptiometry (DEXA) for body compsoiiton; ELISA, RIA and other laboratorial methods used for the quantification of hormones and metabolites, and questionnaires and visual analogue scales. Data will be collected from 20 research participants. We estimate to be generating gigabyte (.csv) amounts of data. The methodology, statistical analysis plan, and a data dictionary will also be shared. Based on ethical considerations, scientific data will be de-identified and shared at the participant level. Data will be made available in .csv format and will not require the use of specialized tools to be accessed or manipulated.

Shared Documents
STUDY PROTOCOL, SAP, ICF
Time Frame
The data will be shared with others by the time the related study is published and will stay available for at least 10 years.
Access Criteria
All datasets that can be shared will be deposited in the NIH-supported Vivli repository which specializes in clinical trial data. Given the sensitive nature of the dataset, de-identified human subjects' data will be made available in Vivli, which restricts access to the data to qualified investigators with an appropriate research question who sign a data use agreement.

Locations