Food Intake-Related Brain and Metabolic Responses in Obesity

Prior treatment

• History of prior metabolic/bariatric surgery;
• Use of medications affecting metabolism or causing weight loss within the past 1 month; body weight fluctuation exceeding 3 kg during the month prior to screening;

Other illness

• Diabetes mellitus;
• Contraindications or allergies to any ingredient in the standardized meal or macronutrient challenges used in this study;
• Central nervous system disorders (e.g., traumatic brain injury, acute cerebral infarction, epilepsy) or psychiatric disorders (e.g., depression, schizophrenia); use of medications acting on the central nervous system within the past 3 months or long-term use;

Lab values

• Severe impairment of liver, kidney, heart, or gastrointestinal function, including alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST) levels \>2 times the upper limit of normal; estimated glomerular filtration rate (eGFR) \<45 mL/min/1.73 m² calculated by the CKD-EPI equation; history of unstable angina or myocardial infarction within the past 3 months, or heart failure classified as New York Heart Association (NYHA) class II or higher; history of gastrointestinal stoma, bowel resection, intestinal obstruction, or peptic ulcer disease;

Other

• Contraindications to MRI, such as implanted metallic devices or claustrophobia;
• Pregnancy or lactation;
• Participation in another clinical trial currently or within the past 3 months; use of nutritional supplements within the past 3 months or long-term use;
• Use of antibiotics or probiotics within the past 1 month;
• Unusual dietary habits; daily alcohol intake \>40 grams, smoking \>10 cigarettes per day, or coffee consumption ≥2 cups per day.

• Obese participants:
• BMI ≥ 28 kg/m²;
• Age 18-40 years;
• Any gender;
• Right-handed.
  • Healthy control participants:
• BMI 18.5-23.9 kg/m²;
• Age 18-40 years;
• Any gender;
• Right-handed.