NCT05748158 · University of Pittsburgh
A Study to Investigate Why Overweight People Regain Weight After Losing Weight in a Behavioral Weight Loss Program
(POWERS)
What this study is about
The goal of this clinical trial is to determine the physiological basis for the differences in weight regain among adults (25-59 years old) with obesity following participation in a behavioral weight loss program.
View original scientific description
The goal of this clinical trial is to determine the physiological basis for the differences in weight regain among adults (25-59 years old) with obesity following participation in a behavioral weight loss program. Eligible participants will undergo a baseline evaluation after which they will enter an up to 20 week behavioral weight loss program with the goal of losing at least 7 percent of their baseline weight within 35 weeks. Participants who meet the weight loss goal will be asked to remain weight stable for 2 weeks after which they will undergo a clinical examination. They will then be observed for 1 year during which they will undergo 2 additional clinical examinations, one 4 months after completing the weight loss program, and the other 12 months after completing the weight loss program.
Interventions
BEHAVIORAL
Weight loss
A behavioral lifestyle program, up to 20 weeks in duration, based on interventions shown to be successful for weight loss such as the Diabetes Prevention Program (DPP), Action for Health in Diabetes (Look AHEAD), and Comprehensive Assessment of the Long-term Effects of Reducing Intake of Energy Study (CALERIE). Weekly sessions, led by experienced interventionists, will provide education and behavioral strategies for weight loss focused an energy-reduced diet and physical activity. Participants must meet the following milestones to continue in the study: * ≥ 2% weight loss anytime between 28 and 34 days after the start of the intervention * ≥ 5% weight loss anytime between 140 and 146 days after the start of the intervention * ≥ 7% weight loss by the end of 35 weeks After achieving ≥7% weight loss followed by weight stability, participants are observed, without further intervention, for 52 weeks.
Primary outcome measures
Weight change from end of weight stabilization following at least 7 percent weight loss to 52 weeks after weight stabilization following at least 7 percent weight loss
Time frame: End of weight stabilization following at least 7 percent weight loss vs. 52 weeks after weight stabilization following at least 7 percent weight loss
Percentage of lost weight that is regained
Weight change from end of weight stabilization following at least 7 percent weight loss to 52 weeks after weight stabilization following at least 7 percent weight loss
Time frame: End of weight stabilization following at least 7 percent weight loss vs. 52 weeks after weight stabilization following at least 7 percent weight loss
Weight regained
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Age: 25 - \<60 years
- BMI: 30 - \<40 kg/m2 at the first screening visit
- Within 5% of current weight, for the past 6 months at the first screening visit
- Able to participate in ergometry testing
- Has a smart phone, tablet or computer with access to the internet
Exclusion criteria
- If 25-29 years old, \> 5% deviation from maximum weight (excluding weights while pregnant) since age 25 years
- 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
- History of pulmonary embolus in the past 6 months
- Cardiovascular disease (e.g. myocardial infarction, stroke, hospitalization for unstable angina, or transient ischemic attack) within the past 6 months
- Current major depressive disorder or history of major depressive disorder within 2 years
- Any regular tobacco or nicotine use in the past year
- Currently engaging in intense physical training or training for a sports event including, but not limited to, a marathon or body building
- Currently pregnant, or less than one-year post-partum or actively planning to become pregnant within the next two years
- Presently classified as being in New York Heart Association Class II or greater or dysrhythmia
- Diabetes (type 1 or 2 - HbA1c ≥ 6.5%, fasting glucose ≥ 126 mg/dL) or currently taking a glucose lowering medication
- Thyroid disease requiring hormones or medication or TSH \< 0.5 or \> 5 mIU/L
- Renal disease requiring dialysis
- Known HIV infection
- ALT or AST greater than 5 times the upper limit of normal or active gall bladder disease
- Significant anemia (Hgb \< 10 g/dL) or thrombocytopenia (platelet count \< 60,000 /mm3)
- 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)
- 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
- Current or past history of anorexia nervosa or bulimia nervosa
- Current or past diagnosis of binge eating disorder
- Diagnosis of other severe psychiatric disorder (e.g. schizophrenia, bipolar disorder)
- Unwillingness to abstain from marijuana/cannabis use for 3 weeks at each of the four assessment time points
- Known or suspected abuse or misuse of alcohol, prescription drugs, or recreational drugs
- Antiretroviral therapy (ART), including treatment for HIV, pre-exposure prophylaxis (PrEP) or post-exposure prophylaxis (PEP) within the past 3 months
- 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)
- Currently taking anticoagulant medication
- Currently enrolled in a supervised weight reduction program
- Prior or planned bariatric surgery, endoscopic therapy, device-based therapy for obesity, liposuction, cryolipolysis, or abdominoplasty
- 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
- Current celiac or diagnosed gluten intolerance or inflammatory bowel disease requiring specialized diet
- Night or rotating shift worker
- Known severe allergy (e.g. anaphylaxis) to nuts or other foods
- Systolic blood pressure (BP) \<90 mmHg and/or diastolic BP \<60 mmHg on 2 measurements during the clinical screening visit.
- 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.
- Metal implants, piercings that cannot be removed, or metal-based tattoos or hair treatments
- Exceeds limitations to fit dual-energy X-ray absorptiometry (DXA) field of view
- Known allergy to lidocaine or acetaminophen
- Non-compliance with appointments or tasks (food diaries, etc.) during the screening phase
- Blood clotting disorder or INR \> ULN or PT \> ULN or (a)PTT \> ULN
- Tendency to form thick or raised scars
- 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
- At high risk for suicide, as assessed by the Columbia-Suicide Severity Rating Scale (C-SSRS)
Where
- New York, New York
- Philadelphia, Pennsylvania
Collaborators
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Tufts University, Columbia University, New York State Psychiatric Institute, Drexel University, University of Pennsylvania, Dartmouth College
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 12, 2026 · Source of record for eligibility and locations