Well, you know, from my practice as a personal coach (which doesn’t have anything to do with sports or fat loss), I can tell you that about half of my clients bring this topic on the table after a while. Which leads me to think that it might have some relevance for you, as well.

When sifting through all the clever literature about fat loss, body weight management, and whatever, you name it, I find it striking, that everybody seems to have a pretty sound understanding on how the metabolism works – in general. But about 95% of what I have seen so far ignores the most important component in the fat loss equation: the brain.

What?

The brain. Ah yeah well, you might say, I know that I need will-power to crave myself through the fourteenth diet this year, and that the brain is what … What?

Nothing like that.

Here’s the story.

The role of carbs

You might know that the brain’s primary fuel is sugar. You might also know (I’m kidding, you certainly know) that in order to get sugar to the brain, eating carbs is a good idea. You may also know that sugar (glucose) is the only fuel that can be used by the brain, as proteins and fatty acids can’t pass through the blood brain barrier. Yes? No! What? Later more.

What happens if you eat carbs? You have an insulin response, i.e. insulin gets released into the blood stream, and the carbs get transported to the body cells, the liver, etc. And some of it ends up in the brain, keeping that hungry thing running. Eventually, the brain consumes about 20% of your total calorie intake, yes it weighs on average just 1.5kg. Current estimates say that the brain alone consumes about 200 g of carbohydrates (not sugar!) per day.

No wonder, that the brain very quickly runs low on sugar.

Now what happens, if the brain goes in an under-sugar (hypoglycemic) state? A very interesting cascade of events is kicked off: the brain eventually activates the stress system! And the stress system triggers the liver to release glucose into the blood stream. At the same time, cortisol is released, preventing the insulin response, so that the sugar indeed ends up where it should: in the brain.

What has that to do with fat loss?

Quite a lot. Let me explain. The brain is actually a lazy piece of meat. Yes. Whatever it does, it tries to do with as less energy consumption as possible. Survival instinct. Now, triggering the stress system is an energy-consuming exercise. So the brain eventually tries to avoid it. Want to know how much additional energy is consumed by stress? You will, soon.

Now, because of our habits, formed from what our parents told us (the trained our nervous system in that way) and maintained by what our social environment tells us, frequent eating is normal. You have to have breakfast. You need to have lunch. Oh yeah, don’t forget the morning snack and the afternoon snack and the TV snack. We’re eating all the time.

And most of the time, we’re eating carbs. Doesn’t matter what kind of carbs you eat. Slow, long, white, brown … you eat carbs. And while the insulin response triggered is different depending on what you eat, carbs (refactored into glucose) end up in your brain.

The downside of this is obvious: the brain doesn’t need to request glucose from the liver anymore, because before your blood glucose level is back to fasting glucose level (typically measured in the morning before the first meal after 8-12 hours of fasting) there’s already new glucose coming in from the next food. Now, because the brain doesn’t need to trigger the stress system anymore to get his sugar, it just doesn’t do it. Even worse: it kind of forgets how to do it. Instead, it will make you feel hungry, so that you eat. Easier than getting stressed.

So you decided to go on that low carb diet, the brain will outright start crying, because you leave it without glucose from the outside, and it can’t activate the stress system (because it forgot). What happens? You go hypoglycemic … under-sugar. So … you need to eat!

Ultimately you end up eating for your brain, not for your body. But because with every meal that is dictated by your brain you also trigger the insulin response, the nutrients are also transported into the rest of the body. Where they are most likely stocked … as … fat.

It is not so much that your body forgets how to burn fat. It is that your brain forgets how to ask for sugar.

The glucose myth

There is more to it. It’s just one third of the truth that the brain can use only glucose. It can indeed use other fuel as well. Now, what that fuel is, and how you can dig into the potential, I will tell you in the next post.

Eat more rarely (the brain can’t deal with negatives, so less often doesn’t mean anything to it.)

If you’re a I-need-food-every-2-hours person, be aware that you are keeping your body on a constant insulin-rush. Insulin takes about 2 hours to be reabsorbed. Eating every 2 hours just keeps your body in a constant anabolic state, growing tissues and fat reserves. If that is what you want (because you want to bulk), that’s what you want to do. However, you won’t lose fat.

I’m not telling you going from where you are to a full intermittent fasting diet, eating once per day. You’d probably die from hypoglycemia first (not kidding!). You don’t want to go to a low carb diet neither, for the same reason.

What you can do to start with are a couple of things:

  1. Increase the interval between the meals, but don’t let yourself go hypoglycemic
  2. When you start to feel hungry, ask yourself if you’re hungry or if it’s just the habit to eat.
  3. Drink water when you feel hungry. Does the hunger persist? Even if so, water will help you gain at least half an hour before eating.
  4. Stop eating cereal bars and fruit. They are both full of sugar and counter-productive to train your brain.
  5. Start eating vegetables. Yes, they are carbs, too, but also lots of fiber. When you eat, eat vegetables first.
  6. Increase your protein intake slightly. You’re not going to switch to protein shakes all day long. Unhealthy. However it helps getting over the hunger, provides some fuel, and helps spacing the meals further.
  7. Don’t binge-eat once you eat. If you’re stuffing yourself with carbs after a 6-hour fasting period, that’s counter-productive, and doesn’t help train your brain.
  8. Manage your stress level. Stress consumes tremendous amounts of glucose.

Questions and comments welcome!