Ketogenic versus low-fat diets to help keep weight off and change energy use and appetite
Ketogenic Diets for Weight Loss Maintenance: Impact on Energy Expenditure and Appetite in Individuals With Obesity
This tests whether a ketogenic diet versus an isocaloric low-fat diet helps people with obesity keep weight off by increasing daily energy use and reducing appetite.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 20 (estimated) |
| Ages | 18 Years to 65 Years |
| Sex | All |
| Sponsor | University of Alabama at Birmingham Academic / other |
| Locations | 1 site (Birmingham, Alabama) |
| Trial ID | NCT06736028 on ClinicalTrials.gov |
What this trial studies
Adults with obesity first complete a 4-week low-energy diet aiming for at least 5% weight loss. Those who achieve the target are randomized 1:1 to six weeks of weight-loss maintenance on either a ketogenic diet or an isocaloric low-fat diet, with the first two weeks as gradual refeeding. Total energy expenditure and measures of appetite are collected during the maintenance phase to determine metabolic and hunger effects of the diets. The intervention duration is 10 weeks and includes behavioral support and calorie guidance.
Who should consider this trial
Good fit: Adults aged 18–65 with BMI 30–45 who can lose at least 5% body weight during a 4-week low-energy diet, are not pregnant or lactating, and do not have medical conditions or medications that affect metabolism.
Not a fit: People with diabetes, prior bariatric surgery, untreated thyroid disease, certain inflammatory or organ diseases, pregnant or breastfeeding people, or those taking weight-affecting medications are excluded and would not be expected to benefit from this protocol.
Why it matters
Potential benefit: If successful, the approach could help people maintain weight loss by increasing daily energy expenditure and reducing appetite, making long-term weight control easier.
How similar studies have performed: Some prior trials show ketogenic diets produce faster early weight loss and can reduce appetite, but clear evidence that ketogenic diets increase total energy expenditure during weight-loss maintenance is limited.
Eligibility criteria
Show full inclusion / exclusion criteria
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%
Where this trial is running
Birmingham, Alabama
- University of Alabama at Birmingham — Birmingham, Alabama, United States (Recruiting)
Study contacts
- Study coordinator: Catia Martins, PhD
- Email: catia197@uab.edu
- Phone: 205-934-7922
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.