Gastric bypass surgeries reduce both food consumption amount and the absorption of nutrition. In this surgery, stomach is downsized and part of the small intestines are disabled in terms of digestion and absorption. So patients feel full with less food and only a portion of what they consume is absorbed. Gastric bypass surgery can be performed with laparoscopic method.

Bypass surgery is considered as an effective method that enables significant weight loss after the operation. Patients lose 70% of their excess weight within two years after the operation. Food contain not only calorie but other substances like vitamin, iron and minerals that keep us healthy. However, since the absorption of such food will be reduced after the operation, external vitamin and mineral supplement is required for life in order to remain healthy.