Metabolic surgery stands among the most effective treatments for obesity and type 2 diabetes, yet its biological mechanisms remain incompletely understood. A recent comprehensive review published in the International Journal of Obesity synthesizes current knowledge elucidating the molecular and metabolic pathways influenced by bariatric procedures. The analysis highlights changes in gut hormone signaling, bile acid metabolism, and energy homeostasis that contribute to the profound improvements seen post-surgery, informing future therapeutic targets for metabolic disorders.