The study adopts a quasi-experimental research design and plans to include 24 hospitalized patients with schizophrenia from 2 hospitals in the central region, based on G Power calculations. This study will be matched based on gender, age (within 10 years), and the same hospital.The participants will be divided into two groups using a single-masked randomized allocation method. The experimental group (psyllium husk group) will consume 10 grams of psyllium husk daily, divided into two doses, and taken approximately one hour before meals. The control group will receive standard treatment, and the intervention will last for 12 weeks. Inclusion criteria are: 1. Diagnosis of schizophrenia based on DSM-V criteria; 2. Age between 20 and 65 years old; 3. Body mass index (BMI) of 24 kg/m² or higher or those who meet more than three indicators of metabolic syndrome. Exclusion criteria are medications for lowering blood glucose, blood pressure, or lipid levels, significant comorbidities such as cardiovascular diseases or cancer, history of neurogenic bowel obstruction or post-weight loss surgery, and patients with prominent psychiatric symptoms who cannot cooperate. Each patient will undergo measurements of weight, waist circumference, body mass index, and blood biochemical analysis data, including fasting blood glucose (FBG), total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and glycated hemoglobin (HbA1c) before the intervention and after 12 weeks
