Does Intermittent Fasting Slow Metabolism? (Myth Debunked)

It’s obvious.

One of the best things that we can do for the body metabolism is to keep it high.

This is especially true if you’re trying to lose weight.

The faster your metabolism is, the more efficient you’ll be at burning calories. That’s one of the reasons why people always say that you should never skip a meal. Because they say your metabolism is gonna slow down without really any real evidence to back it up. It sounds pretty reasonable but it’s completely untrue.

Does intermittent fasting slow metabolism? Find out in this video:

And I used to believe this myth. Which now looking back is just absolutely ridiculous.

I used to think that if I don’t eat, something bad will happen to me. So I followed the common 6 meals a day advice while restricting my calories and, well, I gained weight. A lot of weight. If you wanna know more about the 6 small meals a day myth, then watch the video below.

 

Does Intermittent Fasting Slow Metabolism? – The Myth Explained

The word “Starvation” is this mysterious boogeyman that always gets mentioned by the anti-fasting crowd to scare us away from not even missing a single meal. As if you’re gonna inflict permanent damage to your body and your muscles will somehow start withering away if you skip breakfast or if you skip your post workout meal. 

This is something I commonly get asked. Does intermittent fasting slow metabolism?

Let’s answer that question from an evolutionary standpoint. I always like to go back to ancestral science because it’s how we naturally evolved as human beings. These are the facts, people.

Let’s say you’re in the middle of nowhere, and you can’t find food. This was absolutely normal during the Paleolithic times when feast and famine was a thing. Our ancestors had to hunt for food and they would go through times when food just wasn’t available. If your brain and your metabolism started to slow down if you didn’t eat, well, it would be that much harder to hunt, because you’re weak and not as mentally sharp, and you’d probably be eaten by a larger animal, and we wouldn’t have survived as a species. But we all know that’s not what happened.

The key player in your metabolism – Insulin

First and foremost, you have to understand a little bit of what causes the metabolism to slow down. And really the key player here is the hormone insulin. Insulin is the main switch that gets triggered when you switch from a fed state to a fasted state. Insulin goes up when you eat (fed state) and it goes down when you don’t eat (fasted state). It’s a fat storage hormone. When it’s high, we’re in fat storage mode and when it’s low, we switch to fat burning mode.

You have to understand from a physiological standpoint that your body can only do one or the other. It can’t store fat and burn it at the same time.

If you’re somebody who follows a high carb diet and you eat a lot of sugar and refined carbs and you carry a lot of excess body fat, you develop something called insulin resistance. Because you have this resistance, your insulin levels are elevated and your body doesn’t get the signal to burn fat for energy. Long story short, elevated insulin levels blocks fat burning. That’s not a good thing. So if you can’t access your own body fat for energy, then the only energy you can burn is the fuel that’s coming in through your food. And that’s when things start to go sideways.

Basal Metabolic Rate

Now, let’s talk about how that affects your basal metabolic rate. If you don’t know what that is, it’s the amount of energy needed just to keep you alive. So if you sat on the couch and watched Netflix all day, the amount of calories that you burn during that time is your BMR. Let’s say your body needs to burn 2000 calories every day to keep your body functioning. Well, there’s two different places where you can get those 2000 calories. You can get it from the food that you eat, or you can get it from your fat stores. It’s an either/or scenario.

So the assumption is, if you wanna lose weight, and this is what the general public has been taught, and everyone refers to this as the calories in vs calories out weight loss model. It’s that if you eat 1500 calories, you’ll make up the difference of 500 from your fat stores and your 2000 calorie BMR will stay stable, and therefore you’re gonna lose a pound a week and then if you do that for a year, you’d lose 52 pounds. And we’d all live happily ever after.

Why calories in vs calories out doesn’t work

If that was true, of course, we’d all be walking around with abs, because almost every body i know has done some form of calorie restricted diet. And it’s almost never worked for anybody. In fact, according to a study, going on a calorie restricted diet actually has a whopping 99% failure rate. Ouch.

Now, If only 1500 calories are coming in, you can only burn 1500 calories. Contrary to popular belief, you simply don’t make up the 500 calorie difference from your fat stores. Remember, if your insulin levels are elevated, you can’t access your own body fat as a source of energy. You just can’t. So your body is forced to ramp down it’s metabolic rate instead to compensate for this lack of calories coming in. And this is the problem with the so called yo yo dieting that people often go through. You experience some initial success and you see some of that excess weight come off but this only lasts for so long. And here’s why.

How weight loss plateaus happen

As you start off for example with a basal metabolic rate of 2000 calories, your body eventually turns that down to 1500 calories over time because that’s all that’s coming in. Then you say freak it and you eat 1700 calories because you’re hungry all the time. Now, here’s the crazy part. Even though you’re eating less than you did before, remember, you’re only eating 1700 calories now, but because your metabolism has slowed down to 1500 calories, you’re gonna start gaining back some of that weight that you’ve lost. And this should sound familiar to all the dieters out there, right?

When you go on a diet, you get that initial weight loss, then you hit the dreaded plateau, then the weight starts creeping back up even though you’re following your diet religiously and you can’t seem to figure out why. And people from the outside just assume that you have no willpower and you end up blaming yourself. Hey, leave a comment below if you’ve ever experienced this.

The definition of yo-yo dieting

So then you kinda do it again, but this time, you lower your calories even more. You eat 1200 calories but you’re eating constantly, you’re eating smaller meals, and you’re eating low calorie processed food which usually means low fat with lots of sugar. Well, all of a sudden, your metabolic rate now has to go down to 1200 calories.

Now your body has to slow down basic human functions even more. So you start to feel cold, you feel tired because you have no energy, you’re hungry all the time, and you’re NOT losing weight. And this is what happens to most people. Over many years of yo yo dieting, people who are on a calorie restricted diet, often times, their basal metabolic rate turns into garbage.

Your BMR actually changes depending on the amount of calories coming in. This explains why people hit a wall with their diets even though they’re following it to a tee. It’s not your fault.

How to increase your metabolism

Now, the good news is that the metabolic rate can go up as well.

For example, there’s a study out there where they put people on a four day fast, and they measured their basal metabolic rate in day 1 versus day 3. What you find is that the amount of calories that they’re burning on day 3 is actually 14 percent higher than it was at the beginning which seems counter intuitive.

You might think, why would your BMR be higher when you’re fasting? And the short answer is that the body has simply switched fuel sources. It switched from burning calories from the foods that you eat to burning body fat which is the stored food that you have.

Remember, body fat isn’t just there for looks. It’s stored energy. Think of it as granola bars strapped to your body. All you have to do is give your body a chance to access it.

But again, the key determinant of that is insulin because you have to open up those stores of body fat for you to burn, and that only happens when your insulin levels are low. And the easiest and fastest way to drop your insulin level is? Surprise, surprise. Fasting.

So does intermittent fasting slow metabolism? Absolutely not. In fact, it can actually increase it.

As always, if this was helpful, share it with a friend who could benefit from it as well!