I Can Make You Thin…Insulin – Hormonal Obesity V

By Jason Fung, MD

Click here for Hormonal Obesity Part IPart IIPart III and part IV.
To start at the beginning – start with the Calorie Series here.

According to Hormonal Obesity Theory (HOT), we postulate that high insulin levels causes obesity.  We can give insulin or insulin stimulating drugs (sulphonyureas) and cause weight gain, despite all attempts to lower caloric intake.

If this theory is true, we should also expect the opposite.  That is, if we somehow reduce insulin to low levels, we should expect significant severe weight loss despite all attempts to increase calories.

In fact, this is exactly what we find.  Type 1 Diabetes is an autoimmune disease of the pancreas.  The insulin producing cells of the body are destroyed.  Therefore, insulin levels fall to extremely low levels.  Blood sugar increases in the blood.  But the hallmark of this disease is severe weight loss.

Aretaeus’ classic description of type 1 diabetes “Diabetes is … a melting down of flesh and limbs into urine”.  That is, in spite of whatever calories you try to eat, the untreated type I diabetic is not able to gain any weight.  Until the discovery of insulin, this disease was often fatal.

In essence, insulin is the signal to the body to gain weight.  If we give insulin, the body will gain weight.  If we take insulin away, we will lose weight.  Put another way, insulin is one of the major controllers of the body set weight (BSW).  If insulin levels go up,  our body is commanded to gain weight.  This will now trigger the response to increase eating.  We will become hungry and be compelled to eat.

If that does not work, then we will decrease our Total Energy Expenditure (TEE) or Calories Out so that we will gain weight in response to whatever number of calories we do take in.

Eating more and moving less is the result of obesity not the cause of obesity

As the great Gary Taubes puts is –
We do not get fat because we overeat
We overeat because we get fat

That sets us up perfectly to ask the correct question.  Why do we get fat?  We get fat because our insulin levels are too high.
In a majority of cases, insulin is the main player in obesity.  However, it is not the only hormonal control of weight – cortisol also plays a role.

Cortisol is the so called stress hormone.  If we hypothesize that excess cortisol may also cause obesity, then we should be able to give somebody cortisol and observe weight gain.  We can observe cases where cortisol is overproduced in the body.  This is called Cushing’s disease or Cushing’s Syndrome.  The hallmark of this disease?  Weight gain.

There is a synthetic form of cortisol – a very commonly used as a medication called prednisone, which is a corticosteroid.  It is a powerful anti-inflammatory and often used in the treatment of asthma, lupus and other inflammatory disorders.

So, if we give somebody prednisone, what happens?  They develop what is called cushinoid syndrome.  In other words, these patients look like they have Cushing’s Disease.

Mostly they notice that they gain weight.  There is also a particular distribution to this weight gain which is called truncal obesity, which means that fat is gained on the trunk rather than on the extremities (arms and legs).

What about the opposite?  If we believe that cortisol can cause obesity, then what if cortisol levels were to drop to extremely low levels?
We have this exact situation in the case of Addisons disease.  This also know as adrenal insufficiency.  The adrenal gland produces cortisol and when it is damaged, cortisol levels as well as other hormones go very low.

The hallmark of Addison’s disease?  Weight loss.

Hormones are the key to obesity.  These are causal relationships.  One thing causes the other.  This is a much more powerful relationship than most correlation studies (see rule #2 – Correlation studies are mostly crap)

If we increase insulin, we gain weight.  If we decrease insulin, we lose weight.  Our body weight (as well as everything else in the body) is regulated by hormones.  Such an important physiological variable such as body weight is not left up to the vagaries of daily caloric intake and output but instead is precisely regulated by hormones – mostly insulin, but also cortisol.

This makes a lot of sense when you think about it.  Consider this.  If we eat 2000 calories/day, that amounts to 730,000 calories in a year (2000*365 = 730,000). Many people, gain 1-2 pounds per year.  Not a lot, but over 25 years, this adds up to 50 extra pounds.  In calorie terms, this amounts to a caloric excess of 7,200 calories over 1 year assuming that 1 pound of fat is roughly 3,600 calories.  This is an error rate of not even 1%.

If we are responsible for keeping track of how many calories we eat and how many calories we burn, do you think that we could be so incredibly precise?  Most of us don’t even know how many calories we are eating or burning at any given time!  How can this possibly be controlled by our rational brain?

We don’t control our body weight any more than we control our heart rates.  This goes on automatically under the influence of hormones.  Hormones tell us we are hungry.  Hormones tell us we are full.  Hormones tell us when to increase energy expenditure.  Hormones tell us when to ‘shut down’ energy expenditure.  Obesity is a hormonal dysregulation of fat accumulation.

When we throw these hormones out of whack, we get diseases such as obesity.  If we can understand that obesity is a hormonal imbalance, then we are set up perfectly to ask the next question – how do we treat obesity?

If we believe that excess calories caused obesity (Caloric Reduction as Primary) then the treatment is to reduce calories.  This was a complete and utter failure. If we understand that obesity is caused by too much insulin, then we need to lower insulin.

In fact, we see that our understanding of obesity has really changed very little since the time of William Banting (mid 1800′s).

From the mid 1800′s to the mid 1900′s we believed that sugars and starches caused obesity.  Obesity was treated by reducing sugars and starches.  And hey, guess what, it worked pretty well.

From the 1950′s to the 2000′s we believed that calories caused obesity.  This led to numerous calorie restricted diets – the large majority of which were complete failures.  And hey, guess what, obesity rates exploded.

Now, with a greater understanding of the hormonal underpinnings of obesity, we see that we have come full circle and have recognized again that refined carbohydrates were the cause of the obesity epidemic.  The key is to restore insulin, and to a lesser degree cortisol levels to normal.  The key is NOT balancing calories – it is to balance hormones.

Continue to Exercise series – part I here
Begin here with Calories I
See the entire lecture – The Aetiology of Obesity 1/6 – A New Hope

By The Fasting Method

For many health reasons, losing weight is important. It can improve your blood sugars, blood pressure and metabolic health, lowering your risk of heart disease, stroke and cancer. But it’s not easy. That’s where we can help.

Jason Fung, MD

By Jason Fung, MD

Jason Fung, M.D., is a Toronto-based nephrologist (kidney specialist) and a world leading expert in intermittent fasting and low-carb diets.

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