How Metabolism Affects Weight Loss and Gain
ConditionObesity and Overweight
Trial statusRecruiting
Trial phaseNot listed
Trial typeObservational
Biological sexAll
Age18-70
SponsorUniversity Hospital Schleswig-Holstein
About this trial
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.
Eligibility criteria
This trial accepts healthy volunteersQualifiers
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
Disqualifiers
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)
Trial 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.
Trial design
Design model
Cohort
Time perspective
Prospective
Treatments tested in this trial
Not listed
Trial groups
20 Participants
are grouped into 2 trial groupsGroup A: Lean individual with weight gain difficulties
Group B: Individuals with obesity and weight loss difficulties
Trial outcomes
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.
Time frame
Measured at baseline (Day 1) and after 24-hour fasting (Day 2)Secondary outcomes
1
Correlation Between Fasting-Induced Energy Expenditure Changes and Diet-Induced Thermogenesis
Evaluate how the change in resting metabolic rate (RMR) after a 24-hour fast relates to diet-induced thermogenesis (DIT) following a high-calorie, low-protein meal. This will clarify the interaction between fasting adaptation and meal-related energy expenditure in lean vs. obese individuals.
Time frame
Baseline (Day 1), post-fasting (Day 2), and after the meal test (Day 2)2
Assessment of Metabolic Flexibility via Respiratory Quotient
Determine whether individuals with obesity show a smaller shift in their respiratory quotient (RQ) after fasting and the meal test, indicating lower metabolic flexibility compared to lean participants.
Time frame
Baseline (Day 1), post-fasting (Day 2), and after the meal test (Day 2)3
Correlation Between Weight Gain at 12-Month Follow-Up and Initial Metabolic Phenotype
Body weight (in kilograms) will be measured at baseline and again after 12 months using a calibrated scale. The correlation between weight change over this period and the initial metabolic phenotype (classified as "thrifty" or "spendthrift") will be assessed. The metabolic phenotype is determined by changes in resting metabolic rate (RMR) and diet-induced thermogenesis (DIT), both measured via indirect calorimetry.
Time frame
12-month follow-up4
Correlation Between Weight Gain at 12-Month Follow-Up and Diet-Induced Thermogenesis
Body weight (in kilograms) will be measured at baseline and again after 12 months using a calibrated scale. The correlation between weight change over this period and the magnitude of diet-induced thermogenesis (DIT) will be assessed. DIT is determined via indirect calorimetry after a controlled, low-protein meal. This assessment will help identify whether higher or lower DIT predicts long-term weight change.
Time frame
12-month follow-upSponsors and contacts
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Source ClinicalTrials.gov