RNY gastric bypass is what is known as a restrictive-malabsorbtive procedure. In other words, it restricts your intake by creating a small pouch in the place of the football size stomach, and reduce the ability to absorb by bypassing part of the intestines where most of the abrosption takes place, from the regular route of digestion. So, limited absorption is part of how RNY works. How much malabsorbtion depends on the length of the bypassed intestine. The more the intestine is bypassed, the more the malabsorption. In the past, up to 2/3 of the intestine was bypassed, but this resulted in too much malabsorbtion in many cases, so, the present method bypasses about 1/3 of your intestines. Logically speaking, this means that your ability to absorb is reduced to 2/3 of what it was before. However, it also depends on how far out you are. The further out, the body recovers, and adapts, so some papers I've read say that in the end, you become able to absorb most of what you've eaten. Now, mind you, if you treat your pouch wtih TLC, and eat only what you should eat and only in the amount you should, then, even if you are able to absorb 90% of what you eat, you aren't in any danger of regaining your weight.
There is some catch to this, though. It's said that you recover most of the ability to absorb protein, fat and carbs, in other words, the major nutrients, but this does not alway apply to the minor nutrients--vitamins and minerals, as they are often subject to area-specific absorbtion--certain sections of the digestive route excretes cetain enzymes/intrinsict factors that are essential to the absorbtion of these nutrietents. With these cases, if the specific area is the section that is bypassed with GBS, then, the rate of malabsorbtion can be higher than 50%, actually. In these cases, you will need ample supplementation to ensure that you will get the nutrients you need.
| 
So long as you are putting your best foot forward, then, 
Linear Mode
