Some time ago, I made a post about the under-recognized health benefits of ghrelin, which is much more than just the "hunger hormone":

http://www.obesityhelp.com/forums/VSG/4456478/Controversial- Ghrelin-is-actually-a-GOOD-thing/page,1/action,replies/topic _id,4456478/

Just a bit of background, first.  Studies indicate ghrelin is lowered considerably long-term in VSG surgery patients (and since the DS surgery also includes the VSG procedure, this includes DS patients, as well).  Since 90% of ghrelin is produced by the stomach, and since 90% of that portion is removed during the VSG surgery (and DS), plasma ghrelin levels plummet after these surgeries and, more importantly, they remain low indefinitely. 

By contrast, though there are some conflicting studies, the bulk of high quality studies suggest the long-term reduction of ghrelin for RNY patients is probably negligible vs healthy thin controls.  The reason for this fact is that with RNY surgery, the "remnant" stomach is left intact along with its natural ghrelin production, and the food feedback mechanism is largely restored vs prior to surgery, as shown in this study:

http://www.ncbi.nlm.nih.gov/pubmed/16924271

And with RNY, ghrelin levels no longer rise as one loses weight from the obese starting point (the body no longer fights the weight loss), and after losing the weight, ghrelin levels become normalized with RNY (whereas they remain low indefinitely with VSG or DS).  The primary mechanism for weight loss with RNY is the drastic increase in resting energy expenditure (aka increased metabolism) after eating (an effect which does not occur with VSG) combined with a modest reduction in food intake; whereas, the primary mechanism for weight loss with VSG is solely a reduction in food intake.  Extrapolating from a 2009 Harvard study, if someone with RNY and someone with VSG were to eat exactly the same food after surgery ("pair-fed"), the person with RNY would lose close to twice as much weight because of RNY's metabolic advantage:

http://onlinelibrary.wiley.com/doi/10.1038/oby.2009.207/full

As also noted in this study, this RNY advantage is not due to malabsorption; this and numerous other studies have demonstrated that neither restriction nor malabsorption plays a significant role in weight loss with RNY, and RNY has trivial caloric malabsorption anyway.  In addition, RNY creates significantly healthier cravings for food choices.  See, for example, this 2012 Harvard study re RNY vs VSG and their primary mechanisms:

http://www.ncbi.nlm.nih.gov/pubmed/23044855

Now, let's get to the interesting part re longevity, ghrelin, and RNY.

First, some of you may already know that caloric restriction (CR) dramatically increases lifespan in most animals studied.  But it turns out there may be a causative link with ghrelin (with ghrelin being a good thing).  To quote from a very recent book on ghrelin ("Ghrelin in Health and Disease" by Smith and Thorner):

"These robust effects of caloric restriction, a form of subtle chronic negative energy balance, lend support to the argument that late-onset disorders are the consequence of sustained high levels of substrate oxidation of various tissues.  In the preceding paragraphs, evidence was provided that the key cellular entity involved in promoting central and peripheral attributes of negative energy balance (including that occurring during calorie restriction) is promoted by active ghrelin and neuronal fatty acid utilization. Thus, it is logical to argue that ghrelin plays an important role in the determination of healthy tissue function and longevity."

Then there is this study that found that with CR, the more the body fights the weight loss, the longer the organism lived:

http://www.ncbi.nlm.nih.gov/pubmed/21388497

This last finding is of great importance, because it shows that the benefits of CR are not due to having infinitesimal fat per se, and it suggests very strongly that one or more compensatory mechanisms (with ghrelin being one prime suspect) is involved with the longevity increases of CR.   But with VSG and DS, most of the plasma ghrelin is lost long term.

In addition to the numerous health benefit links I provided in my earlier post (see first link, above), here are two more studies showing the cardiovascular benefits of ghrelin:

http://www.ncbi.nlm.nih.gov/pubmed/15927713

http://www.ncbi.nlm.nih.gov/pubmed/21617846

On the flip side, and we should strive to remain objective, there can be too much of a good thing.  Ghrelin does have its darker side, such as promoting weight gain, liver fat -- and even cancer, such as suggested by this study:

http://www.ncbi.nlm.nih.gov/pubmed/22999388

But it should be noted that CR reduces the risk of cancer while increasing longevity, as has been shown in study after study over decades of research.  And CR does this, while dramatically increasing plasma ghrelin, as shown in this study:

http://www.ncbi.nlm.nih.gov/pubmed/21163280

So it would seem that RNY (but not VSG or DS) would be the ideal recipe for increasing longevity and avoiding age-related diseases such as Parkinson's, Alzheimer's, heart disease, and perhaps even cancer -- because it alone achieves its long-term weight loss and reduction of comorbidities without permanently and drastically lowering ghrelin levels.

As an aside, all bariatric surgeries have some associated regain after their initial weight loss phase.  And on these forums, you almost exclusively hear the bad stories because most people fare pretty well and get back on with their lives (the exception to overall success being lap-band, which, as any good surgeon should tell you, is not a lifetime solution).  But I believe the trick to keeping the pounds off after reaching goal with RNY is: (1) lots and lots of daily exercise to maintain muscle insulin sensitivity, (2) eliminating all artificial sweeteners to lessen cravings for sweet foods, and (3) steering clear of added salt which induces adiposity and can increase appetite (but I'm digressing into some future post with lots more research links, if I can ever get around to it).

It may take decades before there are compelling long term survival studies comparing RNY, VSG, and DS.  No doubt all three surgeries will be very beneficial vs staying morbidly obese, and some surgeries are more indicated for certain people than others (e.g., DS appears best for permanent diabetes resolution and/or for the super morbidly obese).  And of course, nothing in obesity research is simple, so there will be plenty of caveats to what I've laid out.  But for the big picture reasons outlined above and in my previous post re ghrelin, I'll put my money on RNY to provide the greatest improvement in longevity of the three surgeries for most people with 75-200 lbs to lose.  And interestingly, the 2009 Harvard study of mice with RNY showed a dramatic increase in longevity despite some gradual weight regain.

A healthy body will gradually gain weight in the presence of abundant food such as in Western societies.  This is why, despite gazillions of dollars of research and investigation of an insane number of natural and synthetic chemicals, no one has yet found a safe pill to induce permanent and dramatic weight loss.  TANSTAAFL (There ain't no such thing as a free lunch), as Robert Heinlein put it.  RNY works instead by reconfiguring the intestines to create a healthy metabolic response to food in the metabolic disease of morbid obesity.  Ghrelin levels may fall initially but before long they return to healthful levels.  With RNY most people end up with a healthy struggle against weight regain but at a much lower weight. 

And so the bottom line is this re ghrelin and RNY, the next time someone with a different type of surgery brags a little too loudly that they don't have to exercise or try to keep to their weight off, just think quietly to yourself, "Yes, and that's precisely why I hope to live a long time".

Interesting.  That is a ton of information, thank you for sharing!

Nice post. Thanks.

Brian, you are definitely speaking my language!   I've read (and reposted) some of your past posts re Ghrelin and I was thoroughly impressed. I continue to be impressed with the amount of information supported by actual research you include in your well written posts. Thank you for taking the time to write this and share with this community.    

I find the results from the ghrelin studies, paired with the results found earlier this year that suggest the DNA alteration of children born to RNY mothers may lower their risks of obesity, hypertension, and better fat regulation, http://arstechnica.com/science/2013/05/parents-have-gastric- bypass-childrens-dna-may-receive-the-benefits/and the positive physiological changes in our gut microbiota (replaces fattening microbes with slimming microbes) after RNY http://www.reuters.com/article/2013/03/27/us-obesity-surgery -bacteria-idUSBRE92Q0ZQ20130327, to be very compelling that there is much more going on after surgery than just a mere rerouting and restriction...and that's a good thing. I am looking forward to reading what else they discover about WLS in general.  

Again, thank you for your thoughtful and well written posts, I look forward to your future posts. 

A Bit off topic...but I find the gut microbe/fecal transplant concept fascinating.

Very interesting.  Thank you so much for posting this.  Wow... yet more validation as to how happy I am with my RNY.

Wow!! Really fascinating read! Nice to read scientific studies and objective findings as a comparison to the subjective reads on most forums relating to long-term success and/or failure!

Appreciate all the positive feedback (not used to that), y'all!  And thanks very much, IrrepressibleSLP, for those study links and comments.

im hoping this is true I choose rny due to my metabolic disorder before surgery I am 15 months post rny holding steady at my weight lift weights 6 hours a week plus 6 hours a week of cardio have to eat a ton of calories not to loss anything hoping this lasts forever I eat super clean no artifical or empty calorie foods