Surgery Reverses Diabetes – T2D3

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Could Type 2 Diabetes really be a disease that reverses? We’ve outlined in our previous post how most specialists, doctors and researchers view T2D as a progressive chronic disease. That means that once you have it, it will eventually progress no matter what you do. However, in truth, T2D is actually a reversible, curable dietary disease. And I can quite easily prove it to you.

Let me show you several examples. One of the most well studied examples comes from the literature surrounding bariatric surgery. This is commonly called stomach stapling surgery, and there are many kinds.

The earliest surgery was called the Roux-en-Y surgery where the stomach would be cut to the size of a walnut and the small intestines rewired in order for the remaining food to be not properly absorbed into the body. This is an example of a combined restrictive (causing restriction on how much can be eaten) and malabsorptive (food is not properly absorbed) surgery. This surgery has multiple complications, but does tend to work, as you may well imagine.

Another form of surgery is the sleeve gastrectomy, where only the stomach is cut to the size of a walnut. This is a purely restrictive form of surgery and also works quite well. With the stomach so small, it is often impossible to eat very much food at all. Often people will need to resort to a liquid diet. Any attempt to eat more than a thimbleful will result in severe gastric distention (ballooning of the miniature stomach) and results in persistent nausea and vomitting.

A third type of bariatric surgery is the lap band. This involves the surgical implantation of a band that wraps around your stomach, thereby reducing the size to that of a walnut, without actually cutting anything out. It can also be gradually tightened to restrict food.

I don’t really recommend any of these surgeries for anybody, but there is no denying that they can often be effective in the short term. Many of the longer term studies show varied effectiveness, though. However, my point is not to praise or condemn these surgeries. As with anything else in medicine, I suppose they do have their place.

My question is about T2D. What happens when you take a severely obese, diabetic patient and perform one of these surgeries. Surely those patients must have chronic incurable progressive disease? According to conventional thought, the pancreas is ‘burned out’ and nothing you do will change that. Also, as per conventional thought, insulin resistance is high and nothing can change that either. So therefore, since both abnormalities of T2D are irreversible, the diabetes should continue unabated by the surgery. Right? Actually, in virtually all cases, the diabetes completely disappears!

What?! I thought T2D was a chronic and progressive disease! They told me that in medical school! The American Diabetes Association spews that line all the time! The Diabetes Education Centres all say so! WTF??

In fact, the T2D is entirely reversible, even in patients that weigh 500 pounds and have had their diabetes for 20 years. In a matter of weeks, before even any substantial weight loss, the diabetes disappears. Yes. It just goes away.

Let’s look at this study (STAMPEDE) entitled “Bariatric Surgery versus intensive medical therapy for diabetes” published in the New England Journal of Medicine 2012.

Patients were initially randomized to one of three groups. Two different types of surgery were compared with intensive medical treatment – in other words, continuing to take their drugs for diabetes. The results were compared over the 3 years of the study. At baseline, the average age was 48, with a HbA1C of 9.3% (very poor control) and BMI of 36 (obese)

The medical treatment group basically continued on as they had before. Their weight did not really change much and their medication they used for T2D slightly increased over three years. That means their T2D was getting worse, since they required more medication to keep control of their sugars.

But look at both surgical groups. Within 3 months of surgery, the average number of medications was significantly reduce and a number were off meds entirely. The interesting part about these results is that the T2D disappears before most of the weight is lost. Assuming a patient starts off at 400 pounds, after 3 months, they probably still weigh over 350 pounds. So they are still massively overweight, yet the T2D still goes away. We will get to the reason why this happens in a later post, but it has to do with visceral fat.

By 3 years, a full 38% of the Roux-En-Y group had a A1C < 6% compared to 5% of the intensive medical therapy group. Furthermore, many of these were not on medications. This would technically mean that these patients no longer had diabetes. In other words, T2D is reversible – even curable!

Actually, this fact had been known since 1982. The 10 year follow up of a group of surgical patients had shown that many patients maintained normal blood sugars even off medications. Furthermore, the vast majority of patients showed reversibility within 2 months of surgery. It is both rapid and long lasting reversibility. It wasn’t simply their sugars that returned to normal. Many of the metabolic abnormalities seen in T2D reverted back to normal as well.

In T2D, insulin levels are quite high to ‘overcome’ the insulin resistance. You can see in the above graph that insulin levels are dropped quite dramatically by surgical treatment.

In the 1 year after surgery, blood sugars dropped in half, but fasting insulin (a marker of insulin resistance) dropped 73%.  Maximum insulin release dropped 18% since these high insulin levels are no longer needed as the resistance has dropped. Glucose disappearance rates increase as it comes out of the blood much better.

This is quite important. Remember that T2D is a disease of high insulin resistance. The high blood sugars is only a symptom of the disease. This is why treating blood sugars is so ineffective – because it is only a symptom and not the actual disease.

Again, I don’t generally recommend these surgeries for a variety of reasons. However, my point is this. T2D is an entirely reversible disease, even in the extremely obese, with decades of diabesity. It is not a chronic and progressive thing like, say, age. You simply can’t get younger no matter how much you want to. However, T2D is not like that at all. It is fully and completely reversible. It is only a matter of understanding how to reverse it.

But even better – it is reversible within a matter of weeks! With the proper interventions, you simply do not need to suffer from T2D at all. Here’s the most important take home message from all these trials of bariatrics – T2D is a fully curable disease.

Start here with ‘My Journey

Continue to T2D 4 – “Fasting Cures Type 2 Diabetes”

See the lecture ‘The Two Big Lies of Type 2 Diabetes

2017-10-27T22:15:46+00:00 28 Comments

About the Author:

Dr. Fung is a Toronto based kidney specialist, having graduated from the University of Toronto and finishing his medical specialty at the University of California, Los Angeles in 2001. He is the author of the bestsellers ‘The Obesity Code’ and ‘The Complete Guide to Fasting’. He has pioneered the use of therapeutic fasting for weight loss and type 2 diabetes reversal in his IDM clinic.

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28 Comments on "Surgery Reverses Diabetes – T2D3"

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Kash Bhatti

Absolutely true; the interest is in what the switch is that (crude) surgery induces this change – hopefully an area of research if the powers-to-be allow. Any theories yourself?

Dr. Jason Fung: Yes, I believe that bariatric surgery is surgically enforced fasting.

Ahmad Luqman Alias Firdaus Bin Ab Patah
Ahmad Luqman Alias Firdaus Bin Ab Patah

Is ogtt really important to prove this is curable?


Are there studies that show percent that maintain their diabetes-free status at 3 years and 5 years post gastric surgery? and percent who regained weight at 3 & 5 years?

If a person learns how to drive and then subsequently crashes their car, it does not discount the fact that they learned how to drive. If forced fasting (surgery) reversed their Type II Diabetes, and they subsequently return over time to a lifestyle of excessive sugars to bring about the same symptoms, it does not mean that the surgery was not successful. I’ve seen various reports of 50-80% of patients post-op that regain “some” weight, but what does this mean in terms of Type II? There was a study, albeit small by the University of Newcastle which shows that visceral… Read more »
Per-Johan Sundbaum

I’m very greatful that you share all this information !


This post does indeed prove your point.

True, you weren’t touting bariatric surgery, but the
issue of malabsorption cannot be overstated. These
surgeries may help with some diabetes issues, but they
have many more issues exacerbated by malabsorption
of nutrients.

I would hope that someone with diabesity would at
least look into LCHF and IF and try them before going
to such drastic measures as bariatric surgery.

Carb addled people become desperate though.


It’s interesting that the diet recommended for maintenance after duodenal switch surgery (which is more expensive but considered the most effective) is a LCHF one, so I second your comment that people would try the LCHF before surgery. A lifetime of possible malabsorption issues, weak bones, hair loss etc and lifelong supplementation seems a drastic commitment.


Thank you for one more very informative blog post Dr Fung!

I have been following this blog for a few months now and I have one question on fasting rules.
I have been using Broth (bone & veggie) on my fast days and growing quite bored of it honestly 🙂
Is there an alternative drink/juice or even a raw vegetable that i could drink/eat during my 24/36 hour fast?
Anything other than broth is basically the question, a little variety helps sir.
Please advice, thanks in advance.

Bernard P.
clavin, my wife and I have been doing 24 hours fasts for more than four months. On fasting days, we are having one coffee in the morning (no sugar, a little whole milk), and the rest of the day we are only drinking water, in usual quantities. We tried bone broth at the beginning, but quickly stopped because it not necessary. If you are fasting, you have to be fasting… In a previous post or in one of his videos, Dr. Fung has explained that even a little food is enough to interrupt the gluconeogenesis (fat burning) that is happening… Read more »
Cristi Vlad

Bernard, spot on. Fasting is about consuming nothing but water (and in some cases black coffee). But since the proliferation of oil/butter enriched coffee, folks are getting confused. Plus, it’s much easier to control hunger when you fast for 24+ hours because as you progress into the fast and as glycogen gets depleted and you start burning more fat, hunger most often fades away. But if you focus on putting stuff into your mouth, you may not be able to get to these benefits.

Jess Kerr

This brings up a topic i have a question about. So, coconut oil/butter coffee are not okay? I only drink one 10 oz cup on fast days. The rest of the time i drink water and kelp broth, only the broth.


While I only fast one 24hr period every few weeks or so (purely by accident), my typical schedule is 16hr fast per day with an 8hr feed window. For those of you fasting 24hr or more, have you graduated to an 16/8 as more sustainable, or have you/plan to stay with fasting 24/36 hrs as a long term maintenance plan?

My wife and I still use bone broth and “fake teas” (plus I have some coffee in the morning with cream). Fake teas are like hibiscus teas, for instance. I’m trying a 7 day fast now (1st day in though), and we’ve both done multiple 3 day fasts. I personally like having bone broth at night. I usually add hot sauce and salt. For me, I tend to need salt and magnesium (which I’ll take too), or else I get jumpy legs at night and low blood pressure (I’m on an ACE inhibitor and a beta blocker for idiopathic dilated… Read more »

You could also try flavored seltzer waters.


Excited, thanks so much for the info Jason. The big drug companies and shareholders will not be happy with you in sharing this wonderful info to us T2D. I have spent quite a bit of money on medication and consultation fees to specialized for them to feed me drugs and wrong info. God Bless you


[…] Sourced through from: […]

Does anyone else think that a change is BMI is the worst way to look at this? If your BMI decreases by 10 “points” (or whatever units these are), what does that mean? How many pounds is that? You can’t tell unless you know how tall everyone is. For instance, if I say to you that I’ve dropped my BMI by seven “points” (which I have), what does that mean? Now if I tell you I’m about 45 pounds lighter and have lost five inches off my waist due to LCHF and IF, does that makes things more sensible? No… Read more »
Bob, The BMI is a wasted calculation for a number of people and reasons. The standard to look at is Body Fat%, which is very easily and accurately measured. I’ve used scales that measure BF% (typically high by 7-10%), hand-held units (2-5% variance), and calipers with either 1,3, or 7 position measurements. For Men, the one position is within 2% accuracy, more than suitable for health reasons. I can say that I have never been overweight, or had issues with excess body fat, however, my BMI is 27.6. Why should I not be worried?….because i’m 48, 5’9″, 187lbs, and 10%… Read more »

This is an interesting article in Nature that supports what Dr Fung has been saying regarding processed foods.

Food preservatives linked to obesity and gut disease


Interesting article, however, how does the gut bacteria of Mice differ from that of humans? And why is there research trying to find other reasons for Obesity other than the simple fact that people have eaten too much sugar and stored this as fat?


I’ve found processed foods that have low carbs, but have emulsifiers in them. In the article:

“But when immunologist Andrew Gewirtz at Georgia State University in Atlanta and his colleagues fed common emulsifiers carboxymethylcellulose and polysorbate-80 to mice, they found evidence that the chemicals affected the animals’ health. Although their diet was not otherwise changed, healthy mice whose water contained the chemicals became obese and developed metabolic problems such as glucose intolerance.”

These food additives could have a synergistic effect on diets that are high in carbs.


[…] IDM: Surgery Reverses Diabetes – T2D3 […]


I am type 2 Diabetic I take 2000 mg Metformin and 320mg Gliclazide daily.
I intend starting to Fast 1 Day per week.Should I not take my medication on that day.?

My Hb1ac was 58 recently .
Thank you

Dr. Jason Fung: I cannot legally advise you on personal medical issues. Only your doctor can do that.


[…] consider Type 2 Diabetes (T2D) irreversible, fasting has also been long known to cure diabetes. In our previous post, we considered bariatric surgery. While extreme, these surgeries have proven the point that the metabolic abnormalities that […]

john webb

with the sleeve gastrectomy procedure that reduces the stomach to the size of a walnut, surely this impacts hugely on the whole body besides just cutting your appetite? could the good doctors please elaborate on other effects of this operation on the human body?
many thanks,


[…] surprises some people that there are, indeed treatments that cure Type 2 Diabetes (T2D). Bariatric surgery is one such treatment. Fasting protocols have been known for close to 100 years to cure diabetes as […]


[…] consider Type 2 Diabetes (T2D) irreversible, fasting has also been long known to cure diabetes. In our previous post, we considered bariatric surgery. While extreme, these surgeries have proven the point that the metabolic abnormalities that […]


[…] many consider type 2 diabetes (T2D) irreversible, fasting has been long known to cure diabetes. In our previous post, we considered bariatric surgery. While extreme, these surgeries have proven the point that the […]