How Metabolism Affects Weight Loss and Gain

University Hospital Schleswig-Holstein (UKSH)

Status: Enrolling

Conditions: Obesity and Overweight

Study type: Observational

Funder types: Other

Identifiers

NCT06860776

D 481/24

Details and patient eligibility

About

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.

Full 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:

1. 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.
2. 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.

The goal is to identify distinct metabolic patterns. Some individuals may have a "thrifty" metabolism that conserves energy, making weight loss more challenging, whereas others may have a "spendthrift" metabolism that expends more energy, potentially explaining difficulty in gaining weight. Understanding these differences could lead to more personalized and effective weight management strategies.

This study is conducted under strict safety and ethical standards to ensure minimal risk to participants. By examining the relationship between metabolism and weight control, the findings may pave the way for improved treatments for obesity and related weight issues.

Enrollment: 20 estimated patients

Sex: All

Ages: 18 to 70 years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

20 participants in 2 patient groups

Lean individual with weight gain difficulties

Description:

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

Description:

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.