Pilot Study on the Analysis of the Metabolic Phenotype in Individuals With Difficulties in Losing and Gaining Weight
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Enrollment
- 20
- Locations
- 1
- Primary Endpoint
- Identification of Metabolic Phenotypes in Lean vs. Obese Individuals
Study Overview
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.
Detailed Description
This study aims to better understand why certain individuals find it difficult to lose weight while others struggle to gain weight. Investigators believe that differences in how the human body uses energy-referred to as the metabolic phenotype-may play a key role.
Two groups of participants will be compared: one group includes lean individuals who have difficulty gaining weight, and the other group consists of individuals with obesity who have difficulty losing weight. Participants will undergo a series of tests designed to measure how the human body burns calories under different conditions.
The study involves two main components:
- 24-Hour Fasting Period: Participants will abstain from eating for 24 hours to observe how the body adapts by either conserving or maintaining energy expenditure.
- Meal Test: Following the fasting period, participants will consume a specially designed, low-protein meal that simulates overeating. The investigators will measure how much additional energy is burned during digestion, a process known as diet-induced thermogenesis.
A technique called indirect calorimetry will record oxygen consumption and carbon dioxide production. These measurements help calculate resting energy expenditure (REE), which refers to the calories the body burns while at rest, and any changes that occur after fasting and eating.
Study Design
- Study Type
- Observational
- Observational Model
- Cohort
- Time Perspective
- Prospective
Eligibility Criteria
- Ages
- 18 Years to 70 Years (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
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
Arms & Interventions
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.
Outcomes
Primary Outcomes
Identification of Metabolic Phenotypes in Lean vs. Obese Individuals
Time Frame: Measured at baseline (Day 1) and after 24-hour fasting (Day 2)
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.
Secondary Outcomes
- 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))
- Correlation Between Gut Hormones and Changes in Energy Expenditure(Baseline (Day 1), after 24-hour fast (Day 2), and after the meal test (Day 2))
Investigators
Tim Hollstein
Principal Investigator
University Hospital Schleswig-Holstein