Understanding why overweight individuals regain weight after a behavioral weight loss program

Physiology of the Weight Reduced State

Not applicable Interventional University of Pittsburgh · NCT05748158

This study is testing why adults aged 25-59 who are overweight tend to regain weight after completing a weight loss program, by looking at their eating habits, physical activity, and other health factors over a year.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment205 (estimated)
Ages25 Years to 59 Years
SexAll
SponsorUniversity of Pittsburgh Academic / other
Drugs / interventionschemotherapy
Locations3 sites (New York, New York and 2 other locations)
Trial IDNCT05748158 on ClinicalTrials.gov

What this trial studies

This clinical trial aims to investigate the physiological factors that contribute to weight regain in adults aged 25-59 with obesity after participating in a behavioral weight loss program. Participants will undergo a baseline evaluation, followed by a 20-week program aimed at achieving a minimum 7% weight loss. After reaching this goal, they will maintain weight stability for two weeks before undergoing clinical examinations at various time points over the next year. The study will assess changes in energy intake and expenditure, psychosocial factors, and biological markers to understand variability in weight change.

Who should consider this trial

Good fit: Ideal candidates for this study are adults aged 25-59 with a BMI between 30 and 40 who have maintained their weight within 5% for the past six months.

Not a fit: Patients with significant weight fluctuations, cardiovascular disease, or major depressive disorder may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide insights into effective strategies for preventing weight regain in individuals who have lost weight.

How similar studies have performed: Other studies have explored similar behavioral interventions for weight loss, but this study's focus on physiological factors related to weight regain is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. Age: 25 - \<60 years
2. BMI: 30 - \<40 kg/m2 at the first screening visit
3. Within 5% of current weight, for the past 6 months at the first screening visit
4. Able to participate in ergometry testing
5. Has a smart phone, tablet or computer with access to the internet

Exclusion Criteria:

1. If 25-29 years old, \> 5% deviation from maximum weight (excluding weights while pregnant) since age 25 years
2. If at least 30 years old, \> 5% deviation from maximum weight (excluding weights while pregnant) in last 5 years or ≥ 10% deviation from maximum weight (excluding weights while pregnant) since age 30 years
3. History of pulmonary embolus in the past 6 months
4. Cardiovascular disease (e.g. myocardial infarction, stroke, hospitalization for unstable angina, or transient ischemic attack) within the past 6 months
5. Current major depressive disorder or history of major depressive disorder within 2 years
6. Any regular tobacco or nicotine use in the past year
7. Currently engaging in intense physical training or training for a sports event including, but not limited to, a marathon or body building
8. Currently pregnant, or less than one-year post-partum or actively planning to become pregnant within the next two years
9. Presently classified as being in New York Heart Association Class II or greater or dysrhythmia
10. Diabetes (type 1 or 2 - HbA1c ≥ 6.5%, fasting glucose ≥ 126 mg/dL) or currently taking a glucose lowering medication
11. Thyroid disease requiring hormones or medication or TSH \< 0.5 or \> 5 mIU/L
12. Renal disease requiring dialysis
13. Known HIV infection
14. ALT or AST greater than 5 times the upper limit of normal or active gall bladder disease
15. Significant anemia (Hgb \< 10 g/dL) or thrombocytopenia (platelet count \< 60,000 /mm3)
16. Leukopenia defined as:

    Males: WBC \< 3,100 /mm3 or (WBC 3,100 - \< 4,000 /mm3 and at least 1 Duffy antigen (A, B) positive or no result) Females: WBC \< 3,400 /mm3 or (WBC 3,400 - \< 4,000 /mm3 and at least 1 Duffy antigen (A, B) positive or no result)
17. Active cancer or current chemotherapy treatment, or history of cancer requiring treatment in the past 5 years except for non-melanoma skin cancers or cancers that have clearly been cured
18. Current or past history of anorexia nervosa or bulimia nervosa
19. Current or past diagnosis of binge eating disorder
20. Diagnosis of other severe psychiatric disorder (e.g. schizophrenia, bipolar disorder)
21. Unwillingness to abstain from marijuana/cannabis use for 3 weeks at each of the four assessment time points
22. Known or suspected abuse or misuse of alcohol, prescription drugs, or recreational drugs
23. Antiretroviral therapy (ART), including treatment for HIV, pre-exposure prophylaxis (PrEP) or post-exposure prophylaxis (PEP) within the past 3 months
24. Regularly taking medication or supplement known to affect appetite, energy expenditure, or weight (e.g. appetite suppressants, steroids-including inhaled steroids but not topical, alpha-blockers, beta-blockers, certain psychotropic medications)
25. Currently taking anticoagulant medication
26. Currently enrolled in a supervised weight reduction program
27. Prior or planned bariatric surgery, endoscopic therapy, device-based therapy for obesity, liposuction, cryolipolysis, or abdominoplasty
28. Severely restricted diets: Vegan (no meat, fish, dairy, eggs, or honey), very low carbohydrate (\<15% calorie as carbohydrate), very low fat (\<15% calories as fat), or strictly gluten free
29. Current celiac or diagnosed gluten intolerance or inflammatory bowel disease requiring specialized diet
30. Night or rotating shift worker
31. Known severe allergy (e.g. anaphylaxis) to nuts or other foods
32. Systolic blood pressure (BP) \<90 mmHg and/or diastolic BP \<60 mmHg on 2 measurements during the clinical screening visit.
33. Systolic blood pressure (BP) \>160 mmHg and/or diastolic BP \>100 mmHg on at least 2 measurements during the clinical screening visit or resting heart rate \< 45 beats per minute or \>100 on 2 measurements during the clinical screening visit.
34. Metal implants, piercings that cannot be removed, or metal-based tattoos or hair treatments
35. Exceeds limitations to fit dual-energy X-ray absorptiometry (DXA) field of view
36. Known allergy to lidocaine or acetaminophen
37. Non-compliance with appointments or tasks (food diaries, etc.) during the screening phase
38. Blood clotting disorder or INR \> ULN or PT \> ULN or (a)PTT \> ULN
39. Tendency to form thick or raised scars
40. Inability to achieve weight stability (defined in section 4.2.1) during the 2 weeks prior to initiation of the baseline Doubly Labeled Water (DLW) assessment
41. At high risk for suicide, as assessed by the Columbia-Suicide Severity Rating Scale (C-SSRS)

Where this trial is running

New York, New York and 2 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions ObesityWeight lossWeight change trajectoryLifestyle intervention
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.