Preoperative Oral Carbohydrate Loading and Gastrointestinal Recovery After Bariatric Surgery in Metabolic Syndrome

Inclusion Criteria: 1. adults aged 18-65 years; 2. diagnosis of metabolic syndrome (≥3 of the following: elevated waist circumference, elevated triglycerides, elevated blood pressure, elevated fasting glucose, and reduced HDL-C); 3. eligibility for bariatric surgery(body mass index ≥35 kg/m² or metabolic disease with body mass index 27.5-34.9 kg/m²), with planned Roux-en-Y gastric bypass or sleeve gastrectomy; 4. provision of written informed consent and willingness to complete follow-up. Exclusion Criteria: 1. gastrointestinal motility disorders; 2. severe cardiovascular, pulmonary, hepatic, or renal dysfunction; 3. HbA1c ≥8.0%; 4. fasting plasma glucose \>10.0 mmol/L at the preoperative assessment; 5. malnutrition; 6. known allergy to carbohydrate preparations; 7. pregnancy or lactation; 8. previous bariatric or gastrointestinal surgery; 9. chronic use of medications known to substantially affect gastrointestinal motility.