THIN4TWINS

Calorie Absorption?

22 posts in this topic

Hi All- I have been thinking lately about maintenance and trying to hatch a strategy for staying at or below my current weight and I have a nagging questions. Thought somewhere here could probably help me. After RNY Gastric Bypass, how is calorie absorption affected? I have read that after a while, our bodies become more efficient at absorbing the calories in what we eat, but do we absorb all our calories? If not, do we ever get back to where we do absorb all the calories we eat? OR, am I confused? Are absorption issued related strictly to vitamins and minerals? Hope someone can answer...

Thanks!

A~

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can't help you out really, but my nutritionist did tell me that the absorption is with normal calories as well, not just vitamins/meds. not sure though if we eventually absorb it all.

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MiladyB probably can explain things better.. but from what I understand, after about 2-3 years post-op, our bodies will have adapted to the bypass of the intestines to such a point as we no longer have the malabsorption issues in regards to the foods we eat.. Not sure if this would affect our meds or not that far down the line.

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The short answer is that calorie absorption is reduced. Your body can adjust to your new design, but can not compensate for bypassed (unused) small intestine.

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The short answer is that calorie absorption is reduced. Your body can adjust to your new design, but can not compensate for bypassed (unused) small intestine.

That's not the research I've read.. what I've read is that our bodies DO learn to compensate for the bypassed intestines.

Hmmm.. I think this might be a good question for the Dr.. Amy, if you don't mind, I'd like to repost your question in the Ask Dr. Callery section for clarification.

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That's not the research I've read.. what I've read is that our bodies DO learn to compensate for the bypassed intestines.

Hmmm.. I think this might be a good question for the Dr.. Amy, if you don't mind, I'd like to repost your question in the Ask Dr. Callery section for clarification.

I should qualify that not all calories are the same. Calories from simple sugars are the easiest/fastest to absorb, and are probably only limited by the size of our pouch (and whether the sugar causes us to dump). Calories from complex sugars and fat take longer to breakdown and we no longer have the intestinal real estate to absorb it like we did pre-op. Of course this will vary from individual to individual depending on the length of the bypass.

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This is what I remember my surgeon telling me.....

First of all, it depends on how much intestine was bypassed. The most common type of RNY is a proximal (there is also distal, and something else I can't remember). With a proximal RNY you malabsorb around 400 calories per day. Supposedly that 400 calorie deficit is what's called the "honeymoon period". Eventually, our bodies adjust, and we don't have the calorie malabsorbtion anymore. However, the vitamin/mineral malabsorbtion is forever.

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This is what I remember my surgeon telling me.....

First of all, it depends on how much intestine was bypassed. The most common type of RNY is a proximal (there is also distal, and something else I can't remember). With a proximal RNY you malabsorb around 400 calories per day. Supposedly that 400 calorie deficit is what's called the "honeymoon period". Eventually, our bodies adjust, and we don't have the calorie malabsorbtion anymore. However, the vitamin/mineral malabsorbtion is forever.

That's how I understood it to be, as well Sherry.

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I agree with Sherry also that is what my Dr. said....

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I'm almost 4 years post-op and still do not absorb calories from fat or fibrous foods like I did pre-op. If I overdue either...well...I know. Perhaps I'm still in my "honeymoon period" but I doubt it. :)

Edit: I had a distal RNY

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I'm almost 4 years post-op and still do not absorb calories from fat or fibrous foods like I did pre-op. If I overdue either...well...I know. Perhaps I'm still in my "honeymoon period" but I doubt it. :)

Edit: I had a distal RNY

Just curious....how do you know for sure that you don't absorb calories from fat or fibrous foods? Did you have some type of testing done that confirmed that?

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Just curious....how do you know for sure that you don't absorb calories from fat or fibrous foods? Did you have some type of testing done that confirmed that?
I do absorb calories from fat and fibrous foods, just not as much as I did pre-op. Unfortunately, I have had time to figure out the maximum amount of certain fats and fibrous foods I can eat before they start passing through undigested (macroscopically...yes gross). And basically my post-op maximums are much less (still) than my pre-op maximums (assuming these existed). A good example of this is that it's now imperative that I watch the amount of butter I put on my popcorn (does anyone remember Olestra? :eek::eek:)

Also, there is a fundamental change to the way that we break down fats post-op. Before the bypass, the duodenum would sense the presence of fats and gallbladder would provide a controlled release of enzymes (bile salts) to break it down for digestion. After the bypass, we no longer use the duodenum or properly utilize our gallbladder (if it was not removed). There are still enzymes available to break down fats at the "Y" of our RNY, but there is now only a trickle of enzymes available at any given time. Which now makes it likely that we could ingest a quantity of fat greater than the quantity enzymes currently available to break them down. I'm not saying it is impossible that our bodies could eventually compensate for this, I just find it highly unlikely.

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I'm not saying it is impossible that our bodies could eventually compensate for this, I just find it highly unlikely.

But do you have any sort of research on this?

I'm not saying your wrong, but it does go against what my doc has given me for information and it seems it's against what some other TT'er docs have told them. I'd be interested in reading more about it, if you could point out the links- thanks!

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I do absorb calories from fat and fibrous foods, just not as much as I did pre-op. Unfortunately, I have had time to figure out the maximum amount of certain fats and fibrous foods I can eat before they start passing through undigested (macroscopically...yes gross). And basically my post-op maximums are much less (still) than my pre-op maximums (assuming these existed). A good example of this is that it's now imperative that I watch the amount of butter I put on my popcorn (does anyone remember Olestra? :eek::eek:)

Also, there is a fundamental change to the way that we break down fats post-op. Before the bypass, the duodenum would sense the presence of fats and gallbladder would provide a controlled release of enzymes (bile salts) to break it down for digestion. After the bypass, we no longer use the duodenum or properly utilize our gallbladder (if it was not removed). There are still enzymes available to break down fats at the "Y" of our RNY, but there is now only a trickle of enzymes available at any given time. Which now makes it likely that we could ingest a quantity of fat greater than the quantity enzymes currently available to break them down. I'm not saying it is impossible that our bodies could eventually compensate for this, I just find it highly unlikely.

Interesting theory. Thanks for explaining. :) Not sure if I agree with you though, considering the info my doctor gave me.

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That's not the research I've read.. what I've read is that our bodies DO learn to compensate for the bypassed intestines.

Hmmm.. I think this might be a good question for the Dr.. Amy, if you don't mind, I'd like to repost your question in the Ask Dr. Callery section for clarification.

Please feel free to repost....this is all very interesting but it seems like there may be a divide in opinions...I'd like to hear from Dr. Callery!

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Another clue that we continue to be malabsorptive for some caloric intake long term is the farting (and the smell). Increased gas is caused by under digested food making it to the large intestine. I would expect that if the small intestine could completely compensate for the malabsorption from bypass, that the amount of gas produced would return to pre-op levels. Unfortunately, this has not been my experience. :o

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Another clue that we continue to be malabsorptive for some caloric intake long term is the farting (and the smell). Increased gas is caused by under digested food making it to the large intestine. I would expect that if the small intestine could completely compensate for the malabsorption from bypass, that the amount of gas produced would return to pre-op levels. Unfortunately, this has not been my experience. :o

Farting is related to malabsorption?!?!?!? :D If that was the case, I would be as thin as a skeleton. :P

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Farting is related to malabsorption?!?!?!? :D If that was the case, I would be as thin as a skeleton. :P

heh.. you and me both! lol...

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heh.. you and me both! lol...

I'm gonna start eating more beans. I didn't know gas was such a good thing! :D:P;)

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I'm gonna start eating more beans. I didn't know gas was such a good thing!
I guess they really are the "Magic Fruit" :D

Seriously though, the reason we pass more gas is because the our large intestine is trying to do more work (to compensate for the unused small intestine). Unfortunately, the large intestine is not as efficient as the small intestine in digestion and creates this lovely side effect. :(

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Please feel free to repost....this is all very interesting but it seems like there may be a divide in opinions...I'd like to hear from Dr. Callery!

Okay, Amy.. I've reposted your question to the Ask Dr. Callery section, but know that it says the questions to him have to be screened by someone before they'll show up and could take several weeks for a reply. Keep an eye out :)

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Thanks Kel - I will keep an eye out for it!!

A~

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