OK so I have asked this in the middle of a thread before but I still CANT wrap my head around it. Absorption. I have asked about how our stomachs absorb protein after surgery. I got the response, that our stomachs will only absorb about 20 gr of protein in one sitting. If this is true why do I keep seeing postings for like 30/40 gram protein mixes? Does no one know this info, or is it not true or what? I totally believe the person that told me this, I am not saying that he/she was wrong(sorry cant remember who said it) I am just saying that if this is true then I really think it should be shouted from building tops because all I keep hearing about are, " I found this 30 gr protein shake, and I'll drink two and that will be my protein for the day." IF the 20 gr absorption thing is TRUE then people ARENT actually getting what they think they are getting, that is important to know! HELP!

I've heard the same thing so I space my protein out over the day. My shakes just have 22 grams.

I am not a doctor, but from my understanding, Protein is not absorbed by the stomach, period. It is broken down by the stomach and bile acids, and absorbed in the small intestine.

Protein (nutrient) - Wikipedia, the free encyclopedia

"Digestion typically begins in the stomach when pepsinogen is converted to pepsin by the action of hydrochloric acid, and continued by trypsin and chymotrypsin in the intestine. The amino acids and their derivatives into which dietary protein is degraded are then absorbed by the gastrointestinal tract. The absorption rates of individual amino acids are highly dependent on the protein source; for example, the digestibilities of many amino acids in humans differ between soy and milk Proteins[6] and between individual milk proteins, beta-lactoglobulin and casein.[7] For milk proteins, about 50% of the ingested protein is absorbed between the stomach and the jejunum and 90% is absorbed by the time the digested food reaches the ileum.[8] Biological value (BV) is a measure of the proportion of absorbed protein from a food which becomes incorporated into the proteins of the organism's body."

Note the phrasing: "between the stomach and the jejunum." This jibes from what I remember of my physiology classes: the stomach is NOT primarily an absorptive organ; instead, its job is to churn up food and mix it with acid and enzymes for absorption in the intestines (primarily the small intestine for nutrients).

As another case in point, consider that lap sleeve is considered a restrictive, but not malabsorptive procedure. The duodenal switch, on the other hand, is a malabsorptive procedure.

All of this goes to my (educated) guess that the figures about how much protein you can "absorb" in one sitting after lap sleeve being bunk. It's not so much how much you can absorb, because that hasn't changed. Instead, it's literally about how much you can consume -- that's the only thing that's changed (unless you also had your gallbladder out, which DOES affect protein digestion, to an extent).

So, immediately after posting this, I found a LOT of articles on the net referencing Protein deficiencies after VSG. Deficiency due to restriction in intake makes sense, however my understanding is that stand-alone lap sleeve is NOT supposed to alter your basic metabolism. The only thing I can come up with to explain any supposed protein malabsorption would be if the increasingly rapid stomach emptying prevents sufficient pepsin secretion (and overall acid breakdown) for proper digestion. However, I believe that lap sleeve patients would be noticing this and having very noticeably difficult times digesting protein.

One possible explanation for the "protein absorption" myth is that lap sleeve used to be just one part of a two part procedure -- and that procedure DID change absorption (of Proteins and other macro- and micronutrients). So perhaps what we're getting here is a confusion between the old procedure (which was malabsorptive) and the new procedure (which is not).

Also, if the body could NEVER absorb more than 20g of protein at a time -- in other words, if this isn't something that changes w/lap sleeve, then that's another matter. However, I'm dubious of this.

So, I believe that this may be something of a medical "urban legend." I'm STILL trying to track down ANY scholarly evidence that protein absorption changes in ANY way after lap sleeve. Since I'm about to get the surgery myself, it's kinda important to me (I want to be able to get enough protein to not only be healthy, but also build muscle).

Here's what Dr. Jossart had to say:

Re: question about Protein

The VSG does not have significant malabsorption and protein deficiency is essentially unheard of. Any Protein Drink will be fine. Make sure the carbohydrate count is low(usually less than 10gm) as you don't want to consume alot of sugar. Most health food stores sell good quality Protein drinks as well as grocery stores, etc. The general rule is more than 15gm of protein and less than 10 of carbs.

I've heard the same thing, but I've also read plenty of the articles regarding this subject. It appears that most of them are in agreement that the body can and does assimilate as much Protein as we feed it as long as we are also getting in the necessary amino acids that help digest the protein.

The ASMBS says that it is a myth, and here is an enormous article on nutritional guidelines for WLS patients. It explains protein, Vitamin and supplement deficiencies and absorption. It's extensive, and is not VSG specific, but does contain some very impressive information.

http://www.asmbs.org/Newsite07/resources/bgs_final.pdf

Thanks for that, Tiffykins! This whole "20g of Protein max" thing had the smell of an urban legend about it. It's sad that doctors and nutritionists are repeating it, but even there I've found that not all medical practitioners keep up to date with the research.

My primary care doctor pooh-poohed WLS because he said it had a very low success rate compared to diet and exercise (!)

Is it okay to just drink plain Kefir instead of drinking all the chemicals in the prepared drinks? Kefir is a liquid yogurt with a tons of probiotics. Do you think I'll be able to drink liquid yogurt right after surgery or it has to be liquid like water?

Personally, I think someone forgot to tell our bodies all these rules! It makes sense to me that your body will absorb what it needs -what? You're Protein deficient and starving and suddenly catch and kill a wooly mammoth and you're only going to absorb 20g of protein?

But by the same token I totally believe human beings are not only omnivores but opportunists. I absolutely dont believe there's a "perfect" diet out there, there's ways of eating that lead to weight loss, ways of eating that lead to robust good health, ways of eating that lead to strong bones, ways of eating that increase your memory and mental powers but its very difficult to combine them ALL, all the time. This high protein/low carb mix appears to be great for weight loss and that's why people do it and why its recommended NOT because the body absolutely needs x grams of protein per day, or that carbs cause cravings (debatable for many) or that your hair will fall out if you dont eat whatever.

I think making sure you get enough protein is a sensible action to take, in the context of a balanced diet, obsessing over how many grams of it you absorb is just unnecessary (unless of course you're paying through the nose for the shake!).

Edited May 27, 201016 yr by Jachut

Is it okay to just drink plain Kefir instead of drinking all the chemicals in the prepared drinks? Kefir is a liquid yogurt with a tons of probiotics. Do you think I'll be able to drink liquid yogurt right after surgery or it has to be liquid like Water?

Personally, I'd rather do that than drink shakes. I dont fancy the artificial sweeteners and additives in shakes, I dont consider them "real" food, whereas yogurt to me IS real food. I guess some people would worry about the carb content? But I never avoided carbs and lost weight fine, so I'd prefer to yogurt any day.

Personally, I will do what my surgeon tells me to do. I will not chance screwing this up because I make up my own meal plan. If all of you were so successful eating like you did before, why get the surgery?