APA Dictionary of Psychology

a group of surgical procedures used to support substantial, sustained weight loss and improve obesity-related health conditions. It is typically considered for individuals with severe obesity, often defined as a body mass index (BMI) ≥ 40, or ≥ 35 with significant comorbidities, though eligibility increasingly reflects overall health risk rather than BMI alone. Procedures work by restricting stomach capacity, altering nutrient absorption, or both; common approaches include sleeve gastrectomy and Roux-en-Y gastric bypass. Bariatric surgery is associated with improvements in comorbidities associated with higher weight (diabetes mellitus, hypertension, etc.), quality of life, and mental health, but it requires lifelong behavioral changes and medical follow-up. Comprehensive presurgical evaluation, including psychosocial assessment, helps identify risks and prepare patients for postoperative adjustment. Also called weight-loss surgery.