How to Lose Weight I

By Jason Fung, MD

We start 2015 with a new series – How to Lose Weight.  Probably what many people wonder about this time of year.  First and foremost, any rational weight loss program starts with a thorough understanding of what causes weight gain in the first place.  What is the Aetiology of Obesity?

We’ve spent the previous year discussing this question in substantial detail.  There was the 41 part series of posts entitled “Hormonal Obesity”.  You can review it here – starting with post 1.  You may also review our 11 part series entitled “Calories” to review why calories do not actually cause weight gain.  The four part Exercise series reveals why exercise, while healthy and beneficial, is a relatively minor part of weight loss.  I am aware that reviewing over 50 blogs (about 50,000 words) may not be the most fun you have this new year, but hey, are we here to lose weight or have fun?

Once we understand that insulin is the key player in the development of obesity, we can begin to treat it.  Insulin causes obesity so the key to the treatment of obesity is to lower insulin.  Obesity is not a caloric imbalance, it is a hormonal imbalance.  Obesity is a disease of too-much-insulin.  Therefore, the treatment is to lower insulin.  This, of course, is easier said than done.

It is not simply a matter of lowering calories, or lowering carbohydrates, or lowering sugar or lowering processed foods or or increasing fibre or increasing fruits and vegetables.  No, it is a matter of doing all of these things that decrease insulin levels.  There are two main factors that lead to increased insulin levels.  The first factor is the foods that we eat.  Certain foods tend to raise insulin more than others.  There are also foods that protect against insulin spikes.  This is the question which we obsessively think about “What to Eat“.  Should we eat low calories, low carbohydrate, low fat, low animal protein, high fat etc?
But there is an entirely separate stimulus to insulin levels that does NOT depend entirely upon what we eat.  This factor is insulin resistance.  High insulin resistance will lead to high insulin levels.  While fructose does play a role in increasing resistance, there are many other factors as well.  This is the entirely separate question of “When to Eat“. This question is virtually ignored in the vast expanse of obesity literature both on the internet and in academic journals.  Insulin resistance develops over time.  This explains the time dependent factor of obesity.  Most people become obese at a rate of only 1-2 pounds per year.

I plan to discuss the first question of “What to Eat” first.  We will discuss the three major macronutrients of carbohydrates, protein and fats and healthy choices among them.

Then we will discuss the harder question of “When to Eat” and the startling implications.  This leads to the ‘ancient cure’ for obesity that has, until recently, been completely ignored.  This deals with the time dependent factors.  Since high insulin resistance is the disease known as type 2 Diabetes, this is also the foundation of rational treatment for type 2 diabetes.  Drugs for type 2 diabetes, I believe as virtually useless.  This ‘ancient cure’ also works beautifully for type 2 diabetes, which we use extensively in our Intensive Dietary Management Program.  This was demonstrated in our previous post.

That’s the general plan.  So let’s begin.

There are two prominent findings from all the dietary studies done over the years. First, all diets work. Second, all diets fail. What do I mean? Weight loss follows the same basic curve so familiar to dieters the world over. Whether it is the Mediterranean, the Atkins, or even the old fashioned low fat, low calorie, all diets in the short term seem to produce weight loss. Sure, they differ by the amount – some a little more, some a little less. But they all seem to work. However, by 6 months to 1 year, weight loss gradually plateaus followed by a relentless regain despite continued dietary compliance. This occurs regardless of the dietary strategy. In the 10 year Diabetes Prevention Program, for example there is a 7 kg weight loss after one year. The dreaded plateau, then weight regain, follows. So all diets fail. The question is why.

Permanent weight loss is actually a two-step process. There is a short-term and a long-term (time dependent) problem. This resistance to weight loss represents homeostasis. The hypothalamic region of the brain determines the Body Set Weight (BSW). This is our fat ‘thermostat’. Insulin acts here to set BSW higher. In the short term, we can use various diets to bring our actual body weight down. However, once below the BSW, the body activates mechanisms to regain that weight. This resistance to weight loss was first demonstrated by Drs. Leibel and Hirsch in 1984. Obese persons that had lost weight require fewer calories. Their metabolism had slowed dramatically. The body is actively resisting long-term weight loss. This widely known fact has been both proven scientifically and empirically.

Imagine that you set your house thermostat low, and you are cold. You plug in a small electric heater. Soon, the house starts to warm up. Any brand of electric heater seems to work. All heaters work. This is the short-term solution to the problem. After a while, the thermostat senses that the temperature has gone up. So it turns on the air conditioning to bring the temperature back down. Eventually, after a seesaw battle, the house always wins. The temperature eventually drifts down and we are cold again. This is the long-term problem. All heaters fail. The problem is homeostasis. While we have adjusted the temperature, we have not adjusted the thermostat.

Now, let’s put this into obesity terms. High insulin levels set the BSW ‘thermostat’ at a weight that is too high. Now we decide to lose weight. Following any reasonable diet reduces weight in the short term. This is the quick fix – just like the electric heater. What happens in the long term?

The problem of insulin resistance (time dependent factors) has not been addressed. The insulin resistance keeps insulin high. The BSW is still set at a very high level. The body responds to the weight loss by raising the body weight back up. Hormonal signals of hunger are increased, compelling us to eat. If that doesn’t work, total energy expenditure (TEE) is reduced. This was exactly the experience of the participants in the Minnesota Starvation Experiment. As metabolism decreases, it becomes harder and harder to lose weight. Eventually, after a seesaw battle, the BSW wins. The end result is all too familiar – weight regain. The problem is homeostasis.

So there are actually two separate questions to lasting weight loss. There is both a short-term and a long-term question. The short-term question is “What to Eat”. The longer-term problem is why all diets fail. This is the problem of insulin resistance and resetting the BSW. This question revolves around “When to Eat”.  While these two questions are related, they must both be addressed to develop a comprehensive solution to obesity.

Continue to The MultiFactorial Nature of Obesity – How to Lose Weight II
Start here with Calories I – How Do We Gain Weight?

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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