Bariatric Surgery — Diabetes Cure?

You may have heard that bariatric (weight loss) surgery “cures diabetes.” As a result, bariatric surgeries are being done on people at ever-lower weights. But do these surgeries really work, and if so, how? And are they safe?


In December, I attended a program at University of California, San Francisco, about bariatric surgery for diabetes. The speaker explained that these surgeries should properly be called “metabolic surgery,” because they do NOT work primarily by restricting intake or blocking absorption. They work by changing the way our intestines respond to food.

It turns out that the intestines are filled with glands that secrete all kinds of hormones and neurotransmitters. The intestinal glands are responsible for signaling insulin production, promoting storage of starch and fat, appetite control, and a whole lot of other things. The gut does a lot more than just absorb food into the blood. It orchestrates how our bodies use food.

Different parts of the intestine have different glands. So if you rearrange the intestines so that food is kept away from certain glands, and shunted toward other glands, it can change the way we handle carbs, proteins, and fats. One new “metabolic surgery” is called an “ileal transposition.” The surgeon takes a piece from the end of the small intestine (a part of the hindgut called the ileum), and sews it back in at the top of the intestine, right where food comes out of the stomach. Nothing is permanently removed or bypassed, but just moving the glands around causes big weight loss and better glucose control.

How does this work? Even the surgeons who are doing it don’t really understand. It may be that the hindgut produces more of an insulin-promoting hormone called GLP-1, the same one that is promoted by drugs like Byetta (exenatide).

Apparently moving glands that used to be at the end of the intestine, where all the food was already mixed and partially digested, up to the top, where they deal with all the refined foods right off the plate, leads to very different production of insulin and other vital hormones, like being on constant natural Byetta or Januvia. But there are undoubtedly other factors involved.

Note that these positive results were completely unexpected. Doctors thought they were just shortening the intestine or shrinking the stomach so people would eat less or absorb less. They didn’t realize they were screwing around with people’s hormones and body chemicals, but it turns out that may be a good thing. Or it may not.

Some critics argue that our intestines evolved over millions of years, and we have no idea why they are the way they are. If we just start chopping them up and moving them around, there are bound to be nasty long-term effects. But the surgeons would reply that the environment our intestines evolved for is very different from the environment we’re living in now. It may be that our evolved intestines are no longer well equipped for the changed food world, with all its sugars and refined foods.

Is It Good For You?
Many studies show that different kinds of metabolic surgery help control blood glucose. But that doesn’t necessarily make them a good idea. The side effects can be debilitating. They can make your life miserable. I spoke with one woman who had lost 130 pounds and developed near-normal blood glucose after a Roux-en-Y gastric bypass. Her husband, who had left her because she was “too fat”, came back to her.

Success story, right? Maybe (although I don’t know about taking the husband back)… but physically she’s miserable. She can eat only very small amounts, and most foods she can’t eat at all without getting sick. She has constant nausea and frequent abdominal pains. Is this worth it for her? She’s not sure.

We also don’t know yet how long the metabolic “benefits” will last. We do know that weight is often regainedin 2–5 years after surgery. A recent study shows that postprandial (after-meal) glucose levels can remain high in people who have had metabolic surgery, even if their A1Cs indicate that their diabetes is “cured.”

If you’re considering “bariatric” or “metabolic” surgery, I would encourage you to check it out in detail. What are you getting yourself into? If you do go ahead, choose a surgery with the fewest side effects. (Although they all have pretty many, some have fewer than others.) Consult with other people who have had the surgery, including some that are at least two years past their operation. See if it’s still worth it for them.

And consult with our Diabetes Self-Management community. How many of our readers have had, or thought about, bypasses, bandings, transpositions, and other surgeries for diabetes and/or weight? How has it gone for you?

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  • Kim

    When you say “diabetes”, do you mean Type 2? could this type of surgery really help someone with Type 1 to no longer require insulin?

  • David Spero RN

    Hi Kim,

    Unfortunately, these metabolic surgeries will not help Type 1. The jury is still out on Type 2. I apologize for not making that clear.

  • jim snell


    Suspicions confirmed. Thank you for excellent article and depth of data, comments and questions.

    I am not kean mucking with things in my body one cannot easily reverse, modify and or manage.

    Its like my right eye knocked out by stroke and offset in tracking. An external prism while not ideal has given back most (not all) but key parts of my binoccular vision. Attempting to adjust doing tricks on eye muscles is almost impossible and never works well. Like trying to level table by cutting back on legs – that can go on for ever never really getting there. At least external prism I can have modified, play with and generally cope very well.

  • Mary

    I know 2 people who have had this surgery and are more than 2 years into “recovery”. I would take my type 2 diabetes over their “cure” any day!

    Both have to go and get iron shots once a month because they can no longer process iron through the guts. One gained all the weight back and the other didn’t. They both look like death warmed over and basically look very sick. They are very limited in what and how much they can eat. They have gastric trouble (digestive problems) all the time.

    I hate my diabetes, but I have learned to control it with the help of Metformin and a very low carb diet. My Blood sugars stay in normal range most of the time (83 or thereabouts) and my A1C stays around 5, with my low carb diet, exercise and Metformin. I do take vitamins and minerals, which basically consist of lots of Vitamin D-3, magnesium and a good multivitamin/mineral. Recently I began to eat Nopales (cactus) as part of my vegetables every day and this has also helped to lower me to a non-diabetic FBG/BG/PP range.

    I actually have a much less restrictive diet than those 2 people (cousins of mine) I eat more, feel great and am older than either of them, though I look younger, now that they had that surgery, than they do. I weigh less than the one that gained the weight back too.

    If a loved one asked me about this surgery I would say NO!!! stay away!!!!

  • jim snell

    I believe the reason Bariatric surgery has some most curious results on type 2 insulin resistant people is the dramatic cutback on the calorie/carb input to the body and possibly hormone wiring change due to surgery.

    There is much more data and even excellent papers under the ADA banner ( Good grief) that seems to show that:

    a) cut back on the calorie load/pressure to body by at least 20 per cent or more.

    b) insulin resistance drops as excess glucose swept out of body skeletal muscle cells, fat cells and liver.

    c) in many but not all, the pancrease goes back to work – or else the dropped insulin resistance is dropped and body skeletal cells no longer block own made insulin. Remove excess external insulin adds as lows show up all over.

    d) re-establish calorie load and whatever liquid insulin boost really needed.

    e) so far all the differenmt methods from starvation diet, intestine liner and lap band work but the recovery time is shortes on bariatric surgery. The diets and other methods work but take longer to get excess glucose swept out and insulin resistance dropped.

    I would not recommend messing with my internals as pointed out by previous writer. But case clearly exists to carefully manage energy input and burn and stopping any liver glucose leaks so that body glucose storage sites do not get filled.
    Data suggests that on someone who is clearly now type 2 insulin resistant, first step is to get glucose pressure off, up exercise and carefully manage input energy – carbs control in diet.

    It should also be suggested that the word cure may be misapplied in that all one is really doing is the first and most tmportant step in crisis management to stop the rot. As for a full on cure, that is something else.

    Stopping the rot though would be an excellent first step while we pursue longer term cures.