Weight loss surgery involves the following approaches: 

• Restrictive procedures result in a smaller stomach pouch. Normally, the stomach can hold about 6 1/2 cups of food. A surgically modified, smaller stomach pouch holds about 1/2 cup.

• Malabsorptive procedures alter the pattern of flow from your stomach to your intestine, decreasing the number of calories absorbed by the intestine.

• Combination procedures incorporate elements from both restrictive and malabsorptive approaches.