Gastric bypass weight loss surgery patients should be concerned about fat intake and fat absorption. Both affect the health and diet of the weight loss surgery patient who underwent either gastric bypass and gastric banding. WLS patients who report the greatest success eat a diet low in fat.

Fat Absorption:

In a gastric bypass the stomach size is reduced to about a cup and most of the small intestine is bypassed. The stomach outlet is attached to the jejunum (middle section) of the small intestine. Most food absorption occurs in this section. The specialized cells of the jejunum contain digestive enzymes, carrier proteins and other secretions. However, because the digestive tract has been significantly reduced in the bypass there is less time for foods to be absorbed. In the case of gastric bypass the body will absorb fats in limited amounts.

Incidentally, most gastric bypass patients do not tolerate fats in the form of fried food. Eating fried foods can cause vomiting, diarrhea and weight gain. Monounsaturated good fats found in olives, nuts, avocados, olive oil and canola oil should be consumed sparingly. Polyunsaturated fats, the Omega-6 fats found in nuts, seeds, grains, leafy vegetables, soybeans, dairy products, corn oil, safflower oil and soybean oil, should also be consumed in limited quantity. Saturated (animal and dairy fat) and trans fats (hydrogenated oils) should be avoided.

In a lap-banding procedure the small intestine is not shortened or disrupted so the opportunity for full-fat absorption exists as it did before the lap-band was installed. Most lap-band patients do not report the nausea associated with fat intake that a gastric bypass patient reports.