For those scientific folks out there... random question about malabsorption

Yes absolutely correct...and corrected. We absorb 100 percent of simple carbs.

Thank you!

Bruce

The part of the small intestine, the jejunum is the part where many vitamins, included B12, are arbsorbed. Some vitamins just need the length, so  shorter small intestine means less vit absorption (like D3) http://link.springer.com/article/10.1007%2FBF02284452

Many on OH, and even doctors, say that the villi in your intestines (little finger like structures that absorb nutrients) grow larger, or somehow become more aggressive in absorbing calories as time progresses and that growth is the cause of regain.

You cannot find any research to support this 'old wives tale. because THERE IS NONE.  There is NO SCIENTIFIC EVIDENCE that this happens.  I know that 99.9% of the people on this website will argue this point, but from a scientific view (peer reviewed research).  I am happy to be wrong if someone finds the research.  Much of this research comes from people who lost segments of their intestines from cancer or have short bowel syndrome.I have read the research and spoken with researchers. here's what the SCIENCE says. 

When companies have sponsored research into malabsorption, they find that they cannot even find a drug that will stimulate growth in either the number or size or efficiency of the villi,

The researchers believe that regain is a function of people engaging in higher calories eating.

The best study I have come across says:

Long term, post-RNY, you will poop out 10% more of the fat calories than a non-RNYer.  An RYNer will absorb all the protein and carb calories they intake (and have done since the RYN surgery,)  This does not change over time.  This malabsorption may help, but it'a not much of a bonus over the sleeve.

In the end, the current research says we are in control of our own destinies.  Our intestines are not fighting us.

 

Here is one of the best articles:

http://ajcn.nutrition.org/content/92/4/704.full

I hope they are doing a longer term study.

 

 

Donna gave a great summary.

There are a few studies that show long term malabsorption of fat for RNYers. The amounts vary, but I've seen numbers up to 20% permanent fat malabsorption. And a small amount of protein malabsorption that is permanent also.

My surgeon was pretty adamant that malabsorption of calories after RNY was wildly overstated, and that I should never figure that in to my plans. And what small amount there is, doesn't magically disappear after a year or whenever. It starts declining from Day 1 as we heal after surgery, gradually declining.

Parts of our intestines are bypassed in RNY, and much larger lengths in DS. But, our bodies vary -- a lot -- in how long our intestines are. they say our small intestines average about 20 feet, and large intestines are 5 feet long. But the length of small intestines can vary by about 5 feet. And it doesn't correlate to how tall, or large you are. And women generally have longer intestines than men. So even after RNY, your small intestine can be longer than someone without bypass. But the areas where much vitamin and mineral absorption takes place is in that area bypassed, for as long as your RNY is up and running.

But, not a single one of us got super morbidly obese from eating protein. And wayyy too much fat, especially from something like ice cream and sticks of butter, could make you overweight. But fat isn't really to blame. It's the simple carbs that put all of us. All of us. On the operating table. And if we go back to eating those, we will absorb it all, even with the DS, and get back to morbid obesity. Long term success with these surgeries hinges upon figuring out ways to not eat that crap.

I'd like to add a couple of things. Lots of people talk about "the honeymoon period" after surgery. Often, they mean malabsorption of calories. As I wrote above, unless you have a DS, don't bother leaning on that as a crutch.

But what Donna wrote above applies to the REAL honeymoon period -- in our heads. And it's just as strong for VSGers as RNYers. We work our plans really hard, go low carb, exercise maybe -- do things really well for the first year, maybe year-and-a-half. Then we drift off plan, and go back to the decades of bad habits we used to have. We eat more, and more of that is crap. Some only eat enough extra to gain 10 to 20 pounds, and stick there. Some gain back 50. Some gain it all back. As Donna said, it's bad habits and extra food that get us off track, not losing malabsortion. Which is not only a misnomer but a double negative. Miss Madden, my third grade English teacher, would be hopping mad right now.

So much of this is in our heads, not our intestines.

So much of this is in our heads, not our intestines.

I know you're so right... this especially!

 

Thanks! I really appreciate your input on this one... and I do understand it better now with everyone's help!

Thank you to everyone in this thread!  There is a ton of good info in here, and since my father is getting the RNY done later this year, I'm glad to be able to point him to this thread for the explanation.