Zocdoc Answers

Medical questions & health advice by board certified doctors

"How does Roux-en-Y gastric bypass help one lose weight?"

ZocdocAnswersHow does Roux-en-Y gastric bypass help one lose weight?


Does it make my stomach smaller? Will I feel fuller faster?


Surgerical therapy for obesity can be classified as Restrictive procedures, Malabsorptive procedures, or a combination of the two. Roux en-Y is a procedure which relies on a combination of malabsorptive effect and restrictive effect to achieve the weight loss. In a Roux en-Y procedure, the stomach is stapled off in such a way that it becomes much smaller in size. This results in early satiety, meaning patients feel full after smaller meals due to the fact that smaller amount of food fills up the stomach. That is the restrictive part of the procedure. The malabsorptive effect is imparted by the new anatomy that is created during the operation in which a part of the small intestine is "bypassed" (hence the gastric bypass name). So not only do the patients eat less (because of the smaller stomach), the food they eat also isn't absorbed to the same extent because it skips some of the small intestine. This combination of intended malabsorption and restriction (smaller stomach) results in more substantial weight loss. While gastric bypass is a great option for many people, there are strict criteria for BMI, psychosocial stability, motivation and several other factors that predict success and therefore select whether or not a given person is a good candidate for the bypass procedure. Furthermore, it is still surgery, and every surgery has potential complications that go with it. I strongly encourage you to speak to your bariatric surgeon regarding the risks, benefits and alternatives to Roux en Y gastric bypass surgery.

Need more info?

See a dietitian today

Zocdoc Answers is for general informational purposes only and is not a substitute for professional medical advice. If you think you may have a medical emergency, call your doctor (in the United States) 911 immediately. Always seek the advice of your doctor before starting or changing treatment. Medical professionals who provide responses to health-related questions are intended third party beneficiaries with certain rights under Zocdoc’s Terms of Service.