We saw last week with the Biggest Loser study that basal metabolism plummets when you lose weight with calorie reduction. As contestants lose weight, they burn a lot less energy – up to 800 calories per day less than before. Some of that is expected, since there is less body tissue to maintain, but nevertheless, these contestants burn far less than expected even taking this into account. Even 6 years later, their basal metabolic rate (BMR) remains depressed, as do the contestants themselves. The story got a lot of coverage, but one thing was consistently missing. How to fix it.That’s what I’ll show you today, and it’s the opposite of what most people expect.
So, let’s think about this problem in the context of the 2 compartment model of obesity that we have used before. There are two compartments for body energy. We take calories in as food. This gets stored in the short term as glycogen, or long term as body fat. Glycogen is easily converted to energy (calories out), but body fat, not so much. So we can consider the analogous situation where short term energy is stored in a refrigerator and long term in the basement freezer.
Insulin’s role is to direct food into the basement freezer. When there is excess food that can’t be kept in the fridge, insulin directs it to the freezer. This is body fat and manufactured in the liver by the process of de novo lipogenesis. What causes insulin levels to be elevated depends partly on the foods we eat, but also by insulin resistance.
Fructose, for example, plays a key role in elevating insulin resistance which will, in turn raise insulin levels. Insulin resistance leads to high insulin levels, which leads to higher resistance in a vicious cycle. That is, it can be self sustaining.
So during weight loss, if we don’t address the long term issue of insulin resistance, then some of the incoming energy is directed toward storage of fat. At the very least, we won’t be burning fat. Our basal metabolism gets energy from two sources – food, and stored food (fat). If high insulin levels blocks our access to fat stores, then all of our energy must come from food. If we have reduced food intake from 2000 calories per day to 1200, but basal metabolism must also fall from 2000 calories to 1200.
This is the logical response of the body. Where would it get energy from? Fat stores are locked away since high insulin will block fat burning (lipolysis). So, as ‘Calories In’ goes down, so does ‘Calories Out’. This is why the Biggest Loser contestants metabolisms plunged so heavily. This is the fallacy of the Caloric Reduction as Primary crowd. They only care about reducing calories in, and don’t realize that the game is all about ‘Calories Out’.
Consider the analogy of soccer. Soccer’s First Law of Thermodynamics says that to win, you must have more ‘Goals In’ than ‘Goals Allowed’. Goals can’t be created out of thin air. So, therefore if we increase the numbers of ‘Goals In’, we will win every game. So, we move our goalie and position players all to forward and ask them to stay in the attacking zone. Of course, we lose every single game. By trying to increase ‘Goals In’, we’ve increased ‘Goals Allowed’. The mistake is to assume that increasing ‘Goals In’ will not affect ‘Goals Allowed’. Then we blame players for not trying hard enough. But, in truth the strategy was bad.
Same goes for ‘Calories In’ and ‘Calories Out’. Reducing ‘Calories In’ will result in reduction of ‘Calories Out’. You’ll lose every single time, as the Biggest Loser proves. The mistake is to assume that reducing ‘Calories In’ will not reduce ‘Calories Out’. But it does. Every single time. Then we blame patients for not trying hard enough, but in reality, the strategy of ignoring insulin is bad.
How to Fix your Broken Metabolism
So, are we doomed to a life of ever growing waistlines? Hardly. Remember, the key to weight loss is to maintain energy expenditure (calories out). If you simply increase food intake again, you’ll simply increase weight. So, what to do?
There are two compartments here. The body will get energy from food, or stored food (fat). So the answer is to unlock the door which is preventing us from accessing out fat stores. It is the high insulin levels that is keeping all the energy locked away in fat. Insulin is blocking the door so that we can’t get to that basement freezer. Once we understand that, the solution is simple. We need to lower insulin. The key is to release all the pent-up energy stored in the body fat. The crucial junction in weight gain/loss is not the calories, it’s the insulin because that is what opens up the door to release the fat for burning.
Lowering insulin will allow fat burning (lipolysis). This provides our body with lots of energy. If we have lots of energy coming in, the body has no reason to shut down its basal metabolism. The quickest, most efficient way to lower insulin? Fasting. Ketogenic diets will work, too. But remember that insulin has many inputs and is not simply carbohydrates. Cortisol, protein, fructose, insulin resistance, fibre, vinegar and countless other things play a role in determining insulin levels. Generally, though, cortisol and insulin resistance are the things least likely to be treated.
Once the doors to the ‘fat’ freezers are open, the body says, “Whoa, there’s lots of energy here. Let’s burn a little extra”. Studies of fasting show that basal metabolism doesn’t shut down during fasting, it revvs itself up. Four consecutive days of fasting increases basal metabolism by 13%.
Studies of alternate daily fasting (ADF) shows the same thing. Basal metabolism is maintained, even over 22 days of ADF. Even with weight steadily decreasing, the resting metabolic rate is statistically identical at the end of 22 days. You can see from the table below, that carbohydrate oxidation plummets as fat oxidation rises, just as seen previously.
This is an important point. In standard caloric reduction strategies, the body reduces its caloric expenditure to adjust to the reduced caloric intake. Stores of energy locked away as body fat are not available. If your reduce your calories from 2000 to 1200 per day, then your body is forced to reduce calorie expenditure to 1200 per day since it cannot get any from the stored food (fat). Where’s the extra energy going to come from?
However, by lowering insulin drastically during fasting or alternate daily fasting, the body does not shut down. Instead, it switches fuel sources. No food in coming in. Insulin falls. Your body has a choice. It can reduce calorie expenditure to zero, also known technically as ‘dropping dead’. Or, it can force open the reserves and power itself from fat.
Lowering insulin makes it much easier to open up these stores of fat. That it’s normal job. When you eat, insulin goes up, fat goes into storage. When you don’t eat (fast), insulin goes down and fat comes out of storage. Dr. David Ludwig showed a similar result when comparing diets. In his study, he compared the total energy expenditure after weight loss with three different types of diets – low fat (standard advice), low glycemic index and very low carbohydrate.
The low fat diet does nothing to reduce insulin levels. So fat stores are blocked from being used for energy. Basal metabolism drops almost 400 calories per day. But on the other extreme, very low carbohydrate diets would be the diet that lowers insulin the most. This allows access to the basement fat ‘freezer’. Now our body has the energy it needs to start revving up its metabolism.
It works with surgically enforced fasting such as seen with bariatric surgery, too. The one contestant, Rudy Pauls, who got bariatric surgery fixed his wrecked metabolism. So, is it possible? Definitely. Rudy Paul’s metabolism had slowed more than any other contestant. That’s why his weight regain was so dramatic. By forcing himself to fast, he has partially repaired his broken metabolism.
In order to fix our broken metabolism, we need to allow free access to the energy contained within our fat stores. We need to allow fat burning (lipolysis) to proceed normally. We need to lower insulin. The answer is low carbohydrate diets, or even better – intermittent or extended fasting.
Fasting maximally lowers insulin and ignite the flames of fat burning. Caloric reduction wrecked our metabolism by causing it to shut down. How to fix it? Do the exact opposite of what you expect. Push your caloric intake towards zero! This is the George Costanza method. If everything you do makes things worse, do the exact opposite. It does not matter if you think it doesn’t make sense. Do it anyway and see what happens.
The standard nutritional advice given – to Eat Less and Move More is so bad, that doing anything, even the exact opposite beat it.
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.
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.