Yeast Protein Supplementation and Muscle Preservation During GLP-1RA-Induced Weight Loss

The goal of this clinical trial is to evaluate whether yeast protein supplementation can help preserve lean body mass and muscle function in adults with overweight or obesity receiving GLP-1 receptor agonist-related treatment for weight loss. The main questions it aims to answer are: 1. Does yeast protein supplementation reduce the loss of lean body mass during GLP-1RA-related weight loss? 2. Does yeast protein supplementation improve or preserve muscle function? 3. Does yeast protein supplementation affect metabolic status, inflammation, gut barrier function, gut microbiota, and related metabolites? Researchers will compare yeast protein with whey protein and a yeast protein/whey protein blend to evaluate the effects of different protein sources on muscle-related outcomes during GLP-1RA treatment. Participants will: 1. Take the assigned study product every day for 12 weeks, approximately 20 g per day. 2. Return used study-product sachets every 4 weeks so that adherence can be assessed and the next supply can be provided. 3. Attend study visits at baseline, week 4, and week 12 for questionnaire surveys, physical measurements, body composition assessment by DXA, muscle function tests, dietary assessment, and blood sampling. 4. Complete a simplified follow-up at week 8 to record GLP-1RA use and dose changes, study-product adherence, adverse events, and major changes in diet or physical activity. 5. Complete sleep assessment using a wearable sleep-monitoring device and the Pittsburgh Sleep Quality Index at baseline and week 12. 6. Provide stool samples at baseline and week 12 for assessment of gut microbiota and related metabolites.

Inclusion Criteria: * Adults aged 25-50 years with overweight or obesity, defined as BMI ≥24.0 kg/m², who meet the clinical indication for GLP-1RA-related weight-loss treatment. Planning to initiate GLP-1RA treatment, or having initiated GLP-1RA treatment within the previous 4 weeks, and intending to continue treatment for at least 12 weeks. Able and willing to provide written informed consent and comply with the 12-week intervention, follow-up visits, dietary assessments, body composition measurements, muscle function tests, and biological sample collection. Exclusion Criteria: * Known allergy or intolerance to yeast protein, whey protein, milk-derived ingredients, or other components of the study products. Unable to undergo dual-energy X-ray absorptiometry (DXA) or having a contraindication to DXA examination. Sarcopenia at baseline, defined by appendicular skeletal muscle mass index (ASMI) \