How Metabolism Affects Weight Loss and Gain

NCT06860776 | Recruiting

• 1 other identifier: D 481/24
• Study Type: observational
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

This study examines why some individuals with obesity have difficulty losing weight, whereas some lean individuals struggle to gain weight. The investigators will measure how the human body uses energy during a fasting period and after consumption of a specially designed, low-protein meal. By comparing these responses, the investigators aim to identify different "metabolic phenotypes" that affect weight control. Findings from this research may lead to more personalized treatments for managing weight. Participation in this study involves simple tests and basic body measurements.

Conditions

Obesity and Overweight

Keywords

obesity; metabolic phenotype; thrifty; spendthrift; diet-induced thermogenesis; fasting; indirect calorimetry

Outcome Measures

Primary Outcomes (1)

• Identification of Metabolic Phenotypes in Lean vs. Obese Individuals

  We aim to determine whether individuals with obesity (BMI \>30 kg/m²) exhibit a more "thrifty" metabolic phenotype (lower resting metabolic rate \[RMR\] after 24-hour fasting and reduced diet-induced thermogenesis \[DIT\]) compared to lean individuals (BMI 18.5-22 kg/m²) who have trouble gaining weight, hypothesized to show a more "spendthrift" metabolic phenotype (increased RMR after fasting and higher DIT). RMR is measured via indirect calorimetry before and after a 24-hour fast, followed by a high-calorie, low-protein meal test to assess DIT.

  Measured at baseline (Day 1) and after 24-hour fasting (Day 2)

Secondary Outcomes (6)

• Correlation Between Fasting-Induced Energy Expenditure Changes and Diet-Induced Thermogenesis

  Baseline (Day 1), post-fasting (Day 2), and after the meal test (Day 2)

• Assessment of Metabolic Flexibility via Respiratory Quotient

  Baseline (Day 1), post-fasting (Day 2), and after the meal test (Day 2)

• Correlation Between Weight Gain at 12-Month Follow-Up and Initial Metabolic Phenotype

  12-month follow-up

• Correlation Between Weight Gain at 12-Month Follow-Up and Diet-Induced Thermogenesis

  12-month follow-up

• Correlation Between Meal Test Diet-Induced Thermogenesis and Fibroblast Growth Factor 21 (FGF-21) Secretion

  After the meal test (Day 2)

Study Arms (2)

Lean individual with weight gain difficulties

Participants in this group are lean individuals (BMI 18.5-22.0 kg/m²) who have difficulty gaining weight. They will undergo a 24-hour fasting period followed by a controlled low-protein, high-calorie meal test. Researchers will measure their resting metabolic rate before and after fasting, as well as the body's response to the test meal. By comparing these results to those of other groups, the study aims to identify metabolic factors that influence weight gain difficulties and guide future personalized treatments.

Individuals with obesity and weight loss difficulties

Participants in this group are individuals with obesity (BMI \>30 kg/m²) who have difficulty losing weight. They will undergo a 24-hour fasting period followed by a controlled low-protein, high-calorie meal test. Researchers will measure their resting metabolic rate before and after fasting, as well as the body's response to the test meal. By comparing these findings with those of other groups, the study seeks to uncover metabolic factors that contribute to weight loss difficulties and guide more personalized treatment approaches.

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Participants will be recruited from the general adult population, focusing on two specific groups: 1. Lean individuals (BMI 18.5-22.0 kg/m²) who struggle to gain weight 2. Individuals with obesity (BMI \>30 kg/m²) who struggle to lose weight All participants must be generally healthy, between 18 and 70 years old, and report a stable body weight (less than 5% fluctuation) in the last six months. Recruitment will occur via community outreach, advertisements, and existing volunteer registries. Potential participants with conditions or circumstances that could affect appetite, energy expenditure, or study compliance will be excluded.

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• University Hospital Schleswig-Holstein: lead

Study Sites (1)

University Hospital Schleswig-Holstein

Kiel, Schleswig-Holstein, 24105, Germany

RECRUITING

Related Links

• Study Website (German)

Biospecimen

Retention: SAMPLES WITHOUT DNA

Blood, Urine, Saliva

MeSH Terms

Conditions

Obesity; Overweight; Fasting

Condition Hierarchy (Ancestors)

Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Feeding Behavior; Behavior

Central Study Contacts

Tim Hollstein, PD Dr. med.

CONTACT

+4943150022000; tim.hollstein@uksh.de

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: February 28, 2025
• First Posted: March 6, 2025
• Study Start: September 16, 2024
• Primary Completion: August 1, 2025
• Study Completion: August 1, 2025
• Last Updated: March 12, 2025

Record last verified: 2025-03

Locations

DE (1)