Gastric bypass is a surgical procedure designed to limit the amount of food you can eat. While it is meant to be permanent, gastric bypass can be reversed.

Your surgeon will take several steps during the operation:

• Divide and staple the stomach to create a new pouch.
  The pouch, or “new stomach,” is about 90% smaller than your original stomach (the size of a golf ball, compared to a normal stomach, which is about the size of a football).
• Create an opening, called a stoma, that connects the pouch to the small intestine.
  The stoma is very small - about the size of a dime - so that food leaves the stomach slowly.
• Leave the rest of your original stomach intact.
  The bottom part of the stomach - the part not included in the new pouch - continues to secrete gastric juices that empty into the small intestine to mix with food and aid with digestion.

There are three mechanisms by which patients lose weight after gastric bypass:

• The pouch is very small and can only hold tiny portions of food. This helps you to feel full quickly and eat less.
• The opening from the pouch to the small intestine is small, so food moves through your system slowly. This gives you the sensation of feeling full/satisfied for longer.
• Many patients cannot tolerate large amounts of refined sugar after gastric bypass. Eating very little sugar contributes to weight loss.

Small Portions, Small Bites, and Thorough Chewing

Because the stoma is very small, you will need to cut your food into small bites and chew thoroughly. Overeating can damage the pouch and stoma - if you stretch the pouch or dilate the stoma, you may not lose as much weight.

Limited Sugar Consumption

The part of the small intestine that is attached to the pouch struggles to metabolize refined sugar (table sugar). Approximately 50% of people who undergo gastric bypass encounter this problem.

What happens if I eat too much sugar?

• When large amounts of sugar (from desserts such as chocolate bars, cheesecake, or syrup) enter the pouch, your body sends a signal to the pancreas to secrete insulin. Insulin lowers your blood sugar and can cause “dumping syndrome.”
• If you experience "dumping syndrome," you will not feel well for about 5 - 20 minutes. Symptoms may include a cold sweat, an ill stomach, and/or possible diarrhea. In general, this is unpleasant, and you will choose not to intentionally experience it again. Ultimately, this will help you to avoid consuming large amounts of calorie rich sugar, which, in turn, helps with weight reduction.

The normal amount of sugar in items that are not considered desserts or snack food will generally not cause these symptoms.