In the beginning, the pouch holds one ounce of food, eventually expanding to two to three ounces in time. The pouch's lower outlet generally has a diameter of about 1/4 inch. The small outlet delays the emptying of food from the pouch and causes a feeling of fullness.

Gastric bypass operations create a small stomach pouch to restrict food intake and construct bypasses of the duodenum and other segments of the small intestine to cause malabsorption, leading to weight loss. Numerous obesity clinics prefer to do Lap Band adjustable gastric banding and the Promixal Roux-en-Y.

Most people lose weight rapidly for 18 to 24 months after the surgery. As they lose the extra pounds, the obesity-related conditions improve. For an estimated 12 weeks, you'll be on a specialized diet, beginning with a liquid-only meal plan. You'll work up to solids and regular food. However, you will still need to eat small meals throughout the day as eating too much an lead to ramifications.

There are some serious risks when trying to lose weight by reconstructing the stomach. For starters, many people suffer from vomiting if food is not chewed up into small enough pieces. There's also "dumping syndrome" where stomach contents move too quickly through the small intestine, causing nausea, weakness, sweating, faintness, and diarrhea.

And that's not all. Ten to 20 percent of individuals who undergo weight-loss surgeries must undergo another procedure to correct complications. More than half the patients who undergo the surgery suffer from gallstones, while 30 percent of patients develop nutritional deficiencies including anemia, osteoporosis and metabolic bone disease.

Within the first two years of surgery, patients can expect to lose 50 to 60 percent of the excess weight if they do what they're supposed to.