Calorie absorption?

 Does anyone know the relative percentage of calories absorbed post op? Just curious 

 I asked the doctor and the PA this question when I went to my pre admission testing. I was not given a number. I was told that the malabsorption is minimal and the main reason for the weight loss is restriction. 

It would be interesting to see what others have been told. I would really like to see some studies to back up any malabsorption data.

There is no definitive answer, some say that in fact there is very little calorie malabsoption at all, just nutrient malabsoption. Don't account for it, just assume you're getting all the calories you're taking in.

You might be very interested to take a look at my post, "Controversial -- Malabsorption has NOTHING to do with RNY weight loss!"

I post a number of studies, but the biggest is the 2009 Harvard study, which makes it crystal clear that malabsorption is irrelevant to proximal RNY weight loss (and that study also references about 10 other studies supporting this fact).  I put 'controversial' in the post title, but the studies are really very conclusive on this malabsorption question.

I know it seems like restriction is the only thing left to cause weight loss, but it is not a big factor long term, either, as counter-intuitive as that may seem. 

A dramatic increase in resting energy expenditure (think metabolism) for the same small amount of calories, combined with resolving the dopamine- pleasure feedback incentives and other psychological issues associated with over-eating, are the reasons for RNY weight loss success in the long term.  The restriction only plays a minor role, and only then in the short term. 

Consider that in the Harvard study, subjects that were "pair-fed" (meaning they fed non-RNY obese subject the exact same tiny portions and same total food as the RNY subjects ate) lost only 50% as much weight as the RNY subjects.  That is a *massive* difference, and it is because after RNY, your metabolism won't slow down nearly as much with the small amount of food as it would have without the surgery with the small amount of food. 

The studies show that you will always have this huge metabolic advantage with RNY -- good luck to you!

 Brian....thank you so much!