Foods You Cannot Eat After a Gastric Bypass

During gastric bypass surgery weight-loss surgery, the majority of the stomach is separated from the rest of the digestive system, leaving a small pouch approximately the size of a walnut. The small intestine is cut and sewn onto the pouch to complete the new digestive tract. Patients need to follow a very strict diet for about the first 8 weeks. Even after returning to a normal diet, some foods may remain intolerable and others should be avoided or limited.

Solids will be off the menu for the first few weeks after gastric bypass surgery. The post-surgery diet begins with liquids about two days after surgery and leads up to pureed foods, then soft foods before graduating to solids at approximately 8 weeks. This can differ drastically from patient to patient. Patients should make sure they can fully tolerate one texture before moving on to the next.

The National Institutes of Health suggests avoiding foods with a sticky texture after gastric bypass surgery, including white rice and breads, over-cooked pasta, string cheese and peanut butter. These foods may cause pain or discomfort in some patients. White bread may be more tolerable if toasted first. Chewing gum, if swallowed, can block the opening of the small pouch. Symptoms of a blocked pouch include nausea, vomiting and pain.

A study performed by Dr. John Morton of Stanford University found that gastric bypass surgery significantly lowers alcohol tolerance, causing patients to become intoxicated faster and remain so longer than those who have not undergone the surgery. On average, the gastric bypass patients in the study took 40 minutes longer to metabolize alcohol than their non-patient counterparts. Dr. Morton suggests that although post-operative patients are still able to enjoy a glass of wine at home, even that small amount can impair their ability to drive.

One of the risks of a poor post-operative diet is dumping syndrome, which occurs when the food leaves the stomach pouch too quickly and is "dumped" into the large intestine. This can cause weakness, dizziness, cramping, nausea and vomiting. The Ohio State University Medical Center cautions gastric bypass patients to avoid eating foods high in fat or sugars, keeping total sugar or sugar alcohols under 10 grams per meal to avoid dumping syndrome.

Every patient is different, and some of the above foods may not cause a problem for everyone. Some patients may also be bothered by spicy foods or crunchy foods like popcorn and nuts. Others may find they are able to tolerate all foods with little to no difficulty. The key is to eat slowly, chew thoroughly and avoid large meals. Keeping a diary of the foods that cause problems and those that do not may also help to optimize nutrition and maximize the benefits of this weight-loss surgery.