This book provides an overview of surgical bariatric procedures for weight loss and treating obesity-related diseases. It describes the most common bariatric surgery procedures performed worldwide and examines how they have evolved over time in Italy and internationally. For each procedure, it discusses indications, surgical techniques, potential complications, and outcomes related to weight loss and comorbidities. It also covers the problem of weight regain after surgery and discusses different types of revisional surgeries to address this issue.