Understanding how metabolism influences weight loss and gain

Pilot Study on the Analysis of the Metabolic Phenotype in Individuals With Difficulties in Losing and Gaining Weight

Observational University Hospital Schleswig-Holstein · NCT06860776

This study is trying to understand how different people's bodies use energy during fasting and after eating a special meal to see why some people with obesity struggle to lose weight while lean people find it hard to gain weight.

Quick facts

Study typeObservational
Enrollment20 (estimated)
Ages18 Years to 70 Years
SexAll
SponsorUniversity Hospital Schleswig-Holstein Academic / other
Locations1 site (Kiel, Schleswig-Holstein)
Trial IDNCT06860776 on ClinicalTrials.gov

What this trial studies

This observational study investigates the reasons behind the varying weight loss and gain experiences among individuals with obesity and those who are lean. It focuses on measuring energy usage during a 24-hour fasting period and after consuming a specially designed low-protein meal. By comparing the metabolic responses of two groups—lean individuals who struggle to gain weight and obese individuals who find it hard to lose weight—the study aims to identify distinct metabolic phenotypes that could inform personalized weight management strategies. Participants will undergo simple tests and body measurements to gather data on their metabolic patterns.

Who should consider this trial

Good fit: Ideal candidates include lean individuals with a BMI of 18.5-22.0 kg/m² who have difficulty gaining weight and obese individuals with a BMI over 30 kg/m² who have difficulty losing weight.

Not a fit: Patients with prediabetes, diabetes, or other significant medical conditions affecting metabolism or appetite may not benefit from this study.

Why it matters

Potential benefit: If successful, this research could lead to more personalized and effective treatments for managing obesity and weight control.

How similar studies have performed: While this approach is novel in its specific focus on metabolic phenotypes, similar studies have shown promise in understanding energy expenditure and weight management.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Group 1 (Lean): BMI 18.5-22.0 kg/m², reporting difficulty gaining weight
* Group 2 (Obese): BMI \>30 kg/m², reporting difficulty losing weight
* Healthy status as determined by medical history, physical examination, and laboratory tests
* Stable weight (less than 5% fluctuation) over the past 6 months

Exclusion Criteria:

* Prediabetes (HbA1c \>5.6% or fasting blood glucose \>100 mg/dL) or diabetes mellitus
* Conditions affecting appetite or energy expenditure (e.g., Cushing's syndrome, uncontrolled hyper-/hypothyroidism)
* Gastrointestinal disorders that impact nutrient absorption (e.g., inflammatory bowel disease, malabsorption syndromes, ulcers)
* Psychiatric conditions influencing eating behavior (e.g., active depression, anorexia nervosa, bulimia nervosa, borderline personality disorder)
* Acute, unstable cardiovascular disease requiring hospitalization within the last 6 months (e.g., stent placement)
* Cancer that required treatment in the past 5 years
* Chronic kidney disease (Stage IV or higher, per NKF criteria)
* Active infectious disease (e.g., HIV, hepatitis)
* Current nicotine use or nicotine use within the last month prior to screening
* Illicit drug use (e.g., amphetamines, cocaine, heroin, marijuana)
* Regular high-intensity physical activity (≥1 hour/day)
* Non-MRI-compatible metallic implants (e.g., artificial joints, metal plates)
* Pregnancy or breastfeeding
* Use of weight-loss medications
* Clinically significant claustrophobia
* Any other condition not mentioned above that, in the opinion of the investigator, could interfere with study participation or compromise patient safety

Where this trial is running

Kiel, Schleswig-Holstein

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 Obesity and Overweightobesitymetabolic phenotypethriftyspendthriftdiet-induced thermogenesisfastingindirect calorimetry
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.