This study investigates the long-term effects of anti-obesity medications (Semaglutide and Tirzepatide) on energy metabolism (24-hour energy expenditure and substrate oxidation) and body composition via Dual-energy X-ray absorptiometry (DXA)

This study will explore the long-term effects of obesity treatments, including anti-obesity medications (AOMs) such as GLP-1 receptor agonist (Semaglutide) and GIP/GLP-1 receptor agonist (Tirzepatide), on energy metabolism (24-hour energy expenditure and substrate oxidation), body composition (fat mass and fat-free mass). The study will include AOMs may lead to a state of metabolic adaptation, one of the reasons for weight regain. To date, no studies have assessed the effects of AOMs on 24-hour energy expenditure measured by using the metabolic chamber.

Inclusion Criteria:

• Body mass index (BMI) >= 30 kg/m² or >= 27 kg/m² with at least one weight-related comorbidity and stable body weight (±2 kg in prior 3 months)
• informed consent, adherence to study protocol, negative pregnancy test and contraception use (if applicable), and absence of cardiovascular events or end-organ damage.

Exclusion Criteria:

• psychiatric conditions impairing adherence, history of medullary thyroid cancer, pregnancy/lactation
• diabetes

Adults aged 18-75 years with Body mass index (BMI) >= 30 kg/m² or >= 27 kg/m² with at least one weight-related comorbidity (e.g., prediabetes, hypertension, dyslipidemia, sleep apnea, cardiovascular disease) and stable body weight (±2 kg in prior 3 months)