Nutrition gets little attention or respect in medicine, but Dr. Malcolm Kendrick became side tracked by the very powerful and consistent association between heart disease and diabetes:
In short, if you added together what was clear about diabetes and insulin resistance, you got a model of type II diabetes which looked pretty much like this:
- You eat too much food.
- You put on weight.
- As you put on weight you become more and more insulin resistant.
- At first you will develop insulin resistance syndrome.
- If you keep putting on weight you will become so insulin resistant that you will develop frank type II diabetes.
I call this the ‘blowing up a balloon’ theory of diabetes. As a balloon expands you have to blow harder and harder to overcome the resistance. As you get fatter and fatter you need more and more insulin to force fats into fat cells. As with many things in medicine this is a nice simple story. It is also very easy to understand, and it is tantalisingly close to being correct.
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Beginning with the most obese group people on the planet earth, namely Sumo wrestlers. I wanted to know how many of them have diabetes, and it did not take long to discover that, whilst in training, none of them have diabetes.
I then searched for the opposite end of the spectrum. Were there people with no adipose tissue, and how many of them had diabetes? Surprisingly, there is one such group, the least obese people on earth. They are those with Beradinelli-Siep lipodystrophy. This is a genetic abnormality which means that these poor unfortunates have almost no fat cells. How many of them have type II diabetes? Well, all of them actually.
I then looked for the population with the highest rate of diabetes in the world. This happens to be the Pima Indians of North Mexico/Southern US. I have seen figures reporting that over 80% of adult males Pima Indians have type II diabetes. It may even be more. And yes, they are very obese.
However, there are two other very interesting facts about the Pima Indians. First, they have a very low rate of heart disease. Or they did last time I looked. Perhaps most importantly, in their youth, when they are not obese, they produce far more insulin in response to food than ‘normal’ populations. Or, to put this another way, they are hyper-insulinaemic before they are obese, and long before they become diabetic. So their excess insulin production is not a result of becoming fatter. The causal chain is the other way around.
I have found that if you speak to most doctors about these facts, a look of complete incomprehension passes over their faces. ‘That cannot be right.’ Of course if you believe in the ‘blowing up a balloon’ model of diabetes, then the Pima Indians, Sumo Wrestlers and those with Beradinalli-Siep lipodystrophy do not make any sense. However, in science, when observations do not fit your hypothesis, it is the hypothesis that needs to change, not the facts.
Just to summarize these ‘paradoxical’ facts:
- You do not need any fat cells to develop diabetes/if you have no fat cells there is a 100% probability that you will be diabetic.
- You can be very , very, obese and not have diabetes.
- You can have increased insulin production long before you become obese (and/or insulin resistant). You become obese later.
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However, luckily, there is another model that fits all the facts. One that I prepared earlier:
- You produce too much insulin.
- This forces your body to store fat.
- You become obese.
- At a certain point insulin resistance develops to block further weight gain.
- This resistance becomes more and more severe until…
- You become diabetic.
This model explains the Pima Indians. Can Sumo wrestlers be fitted into this model? Yes, with a couple of addendums. Sumo Wrestlers eat to become fat, because added mass provides a competitive advantage if you are trying to shove someone else out of a small ring, before they do it to you.
To achieve super-obesity, they wake up, train for two hours, then eat as much as they can of a high carbohydrate, low fat, broth. They then lie about for a few hours allowing the high insulin levels created by the high carbohydrate diet to convert excess sugars to fat, storing this in adipose tissue. Later on they train very hard again, then eat, then sleep. Rpt.
The reason why they do not become diabetic is on this regime is simply because they exercise very, very, hard. They burn up all the sugar/glycogen stores in the liver and muscle whilst exercising, which means that when they eat, the sugar(s) can – at least at first – be easily stored in muscle and liver (so there is no insulin resistance to overcome). However, once these guys stop training, things do not look so good. Diabetes lurks..
Those with Beradinelli-Siep lipodystrophy have the reverse problem to Sumo Wrestlers. Because they have no fat cells there is nowhere to store excess energy to go. If they eat carbohydrate/sugar, the first 1,500 calories can be stored as glycogen – after that there is nowhere left. If the liver converts sugar to fat, there is nowhere for that to go either. So, you get ‘back-pressure’ through the system. It doesn’t matter how high the insulin level gets, if you have nowhere to store energy you have nowhere to store energy. End of.
Whilst those with lipodystrophy cannot tell us much about diabetes and obesity in ‘normal’ people. This condition does make it very clear that diabetes – insulin resistance, high insulin and high sugar levels – is primarily an issue with energy storage and how the body goes about this storage, and the role that insulin plays. If there is somewhere for excess energy to go easily, insulin levels will not go up, and nor will blood sugar levels.
But what of ‘normal’ people. Can normal people be fitted into the updated model of type II diabetes? Well, of course, they can. But you need another step in the new model, the first step. Which means we have a new causal chain, and it looks something like this ‘You eat too much carbohydrate.’ Adding in this step gives us the new model:
- You eat too much carbohydrate/sugar.
- You produce too much insulin.
- This forces your body to store fat.
- You become obese.
- At a certain point insulin resistance develops to block further weight gain.
- This resistance becomes more and more severe until…
- You become diabetic.
(Hat tip to Mangan.)