Question:
Anyone know how much mal-absorbion of calories with RNY?

Do we absorb all the calories we eat with rny surgery? Is there a percentage of the calories absorbed?    — kathysews (posted on January 18, 2009)

January 18, 2009
It is my understanding that you absorb about 50-75% of what you take in, depending on who you talk to. I would recommend that you ask your bariatric surgeon/nutritionist that very question and attend seminars and research the procedure as much as possible. Best of luck, Dawn Vickers, RN, BLC, CLC
   — DawnVic

January 18, 2009
Also I am 2 months post-op and will see my Dr. next month and will ask him but does anyone know of any web site on this issue?
   — kathysews

January 18, 2009
Kathy, Dawn is telling you right. The reason you lose weight with the RNY is not so much that you are eating so little, but because the food goes from the pouch to a farther point in your small intestines and you lose weight due to absorption. This is why it's so important to eat the protein and take the vitamin and food supplements. As a lady, iron and calcium are very important issues for you, and like most medicines, you may have to take the liquid forms for awhile. It does get easier to take the pills farther on down the road. I am just past the six month mark and can take them a few at a time, and spaced over a 30 minute time period. Eating small bites and chewing them thoroughly helps you get the most out of what you eat. Good luck on your journey. I've lost over 130 lbs total, and about 100 since the day of my surgery, even tho I can't exercise like I'd like to due to back injuries. You'll do well, but please be careful to eat the protein, calcium, iron, and get the B-12. Dusty @};-
   — Dusty Ray Vaughn

January 18, 2009
Nope we don't...but it seems like we do sometimes! It seems like we malabsorb far more nutrients that the calories we eat! I gained weight and was malnourished! WHO KNEW??? How does THAT happen? LOL It's hard to find percentages...but I did find an answer here at one hospital. It said " Proximal: The most common surgical weight loss procedure today, this is the least aggressive gastric bypass. It reduces absorptive capacity of the small intestine by 20 percent. Five-year weight loss averages 50 to 75 percent in most studies. Medial: This moderately aggressive gastric bypass reduces the absorptive capacity of the small intestine by 50 percent. Five-year weight loss averages 70-80 percent in most studies. Distal: This most aggressive gastric bypass reduces the absorptive capacity of the small intestine by 70-80 percent. More than half of calories ingested are not absorbed. In a study conducted by Surgical Weight Loss Clinic in Tacoma, patients had lost 89 percent of excess weight after five years. The distal patient must take more vitamin, mineral and protein supplements than other bypass patients. The five year weight loss averages 75 to 85 percent." https://www.fhshealth.org/Bariatric/typesOfSurgery.asp
   — .Anita R.

January 19, 2009
After i slept on this question...The more I thought about it and I believe Dawn's answer is a combo or avearage of all three types of RNY...BUT the distal is so rare and I had never even heard of the medial until very recently...I believe the info I found is correct and the reason why is this...Imagine the small intestine as a 12 inch ruler (Which it is not, but for visual purposes)...Medial being the center cut at 6 inches...That is 50%...The proximal (most common and shortest cut) is about half of making it about 20-25 %....And the distal is the longest cut...making it 70-75%...Now...THAT makes sense in terms of math...As with all people, you can probably add or subtract 5% because our bodies often function better or worse than average or expected!
   — .Anita R.

January 20, 2009
Anita hit the numbers very accurately. I would only add that over time the receptors in your intestines (the villi) actually regenerate- so any measure of malabsorption from the first 18 months is diminished over the next few years.
   — SteveColarossi