The Metabolic Damage Myth

Busting another fitness myth with the power of science.

Media and the more agressive representants of the body positivity movement promoted the idea that dieting is bad. Their idea is that being in a caloric deficit for a more or less extended period of time permanently damages the metabolism. Therefore you will be dooomed forever to eat a ridiculously low amount of calories otherwise you will become fat. Gladly there is plenty of good evidence on this subject, so let’s take a look at it and once and for all get rid of this myth!

Before we jump into the science and investigate what is the reason for weight loss plateaus and how to overcome them, we need to make sure we know some basic terminology.


Metabolic rate describes the amount of calories your body uses to cover basal body functions (like digestion), exercise (running, lifting) and other movements (walking, fiddling). It is a function of bodyweight, gender, lifestyle and genetics and therefore can vary wildly between seemingly similar individuals. The amount of calories you eat that keeps your body weight stable, is your metabolic rate.

Metabolic damage is the idea that the metabolic rate gets permanently reduced (damaged) by weight loss interventions. I am going to explain to you why this phenomenon is misunderstood and what really happens when people lose weight for extended periods of time.

Starvation mode describes the idea that the body switches to “starvation mode” after a longer period of weight loss as a mechanism to prevent starving to death. This emergency mode should keep dieters completely from losing any weight. You don’t have to think too long about this to figure out how absurd this idea really is, as it would make starvation impossible, and sadly we know that this isn’t the case.

Is permanent metabolic damage a thing?

Now that we have defined the basic terminology, let’s dissect the idea of metabolic damage. Luckily, there is plenty of good research to look at, and we are not looking at our average Jane who does a juice-cleanse and loses 2kg and yoyos up 3kg a week afterwards, thinking her metabolism is damaged but really binged on cupcakes. Or even worse: the participants of Biggest Loser who are crash-dieting in a non sustainable and -I would allow myself to say- outright dangerous (and stupid) way. We have hard data on people who were close to real starvation and got back to normal levels of body fat.

Namely the Minnesota Starvation Experiment, where volunteers were dieted down to better understand the physiology and psychology of starvation; and a wide range of research on anorexia nervosa patients. Dr. Zinchenko and Menno Henselmans worked their scientific magic and came to the conclusion that metabolic damage does not exist!

When you are in a calorie restricted state, your body slows down and expends less energy. When you increase your calorie intake and start eating more, your body starts expending more energy.

Dr. Anastasia Zinchenko, 2017

Therefore starvation mode is also a myth, or at least misunderstood. It is just our body reacting to an energy deficit, slowing down certain metabolic pathways to help save energy (like reducing thermogenesis). However, it cannot prevent you from losing body weight as long as your energy intake is low enough! Our body always needs energy, no matter how efficient it becomes in reducing energy expenditure.

Acute changes in energy intake – such as eating less or eating more – can decrease or increase your RMR (resting metabolic rate). But then, within one to three days after you stop dieting and return to your maintenance energy intake, your basal metabolic rate will also increase. The human metabolism is flexible and adjusts to changing conditions quickly.

Dr. Anastasia Zinchenko, 2017

This is what we call metabolic adaptation and we now know that this adaptation is perfectly normal. We just have to take it into account when dieting.

What keeps you from losing fat

We probably all have experienced weight loss plateaus during a diet. Certainly there is something happening that makes it harder and harder to reach low body fat levels. What is happening there?

Underreporting is a common cause for weight loss stagnation. As we diet, also our brain starts fighting the process and makes it easier to “forget” certain things that we eat. We also often just get sloppy with tracking as we start getting tired of it. There are many factors here playing together, making us overconsume calories, reducing the deficit we think we created.

Overestimating activity is especially a problem for people who use activity trackers and take the “calories burnt” that the device tells them to calculate their deficit. Forget those numbers, they are notoriously inaccurate! It is difficult to calculate the amount of calories exercise burns, so don’t just even bother. Use a simple formula and adapt to the feedback your scale gives you. Activity trackers are only useful to count steps and to make sure your activity doesn’t decrease during a diet.

Metabolic adaptation as mentioned above, is really a concern once you reach lower body fat levels. Your body starts down-regulating non-essential “calorie sinks” to prevent you from further losing fat. This makes it harder to progress, but not impossible! You just have to lower your calorie intake (or increase your output) to reestablish a deficit. No magic needed, just a little more hard work.

Also keep in mind that for most people fat loss is not a linear process and plateaus happen before the next drop occurs. So stay calm, and stick to your diet, progress is just around the corner!

Notice the green line (bodyweight median). Plateaus occur just before the next bout of progress. The red line represents the trend and clearly shows good overall progress.

How to keep losing fat

You want to keep losing fat, but sticking to your diet becomes increasingly difficult and progress grinds to a halt? Here are a few strategies how to get the scale moving down again.

Eating more seems counterintuitive, but many people struggle with their diet because it is overly restrictive or started with a gigantic calorie deficit. Compliance becomes an issue, often leading to cheat meals or outright binges. Those untracked meals are often enough to blow your deficit and make weight loss impossible. By choosing a less severe calorie deficit, you can make it easier to stick constantly to your diet, making progress again. E.g. if your maintenance calories are 1500 but you somewhere read that you need to cut with a 500kcal deficit, you land on 1000kcal. This is very low and probably will provoke the problems mentioned above. But you could cut at 1200kcal, take a little more time at “only” a 300kcal deficit, but make diet compliance much more easy.

Eating more also gives you the possibility to implement diet breaks or refeeds, which improve compliance and may help combat metabolic adaptations, making it a little easier to progress again.

Eating less is sometimes the only thing you can do to start losing weight again. You just eat too many calories. Make smarter choices and save as many calories as possible, often cutting carbs and fats to a minimum. Think berries instead of bananas. Courgettes instead of carrots. Chicken breast instead of steak. Yes, this is often challenging, but it has to be done and you can still eat great meals while doing so.

Moving more is, similar to eating less, quite unpopular, but in our quest to create a calorie deficit, often needed. Maybe you can squeeze in an additional training session, but often it is enough to up your daily step count. This is especially true if you are already very low on your calorie account, such as a petite female on a contest prep eating around 1000kcal. Going even lower will make it nearly impossible to get your required protein in and it makes more sense to add cardio and/or more steps to your routine.

Moving less can be useful for personality types who like to “overdo” the good stuff. Training, cardio, but also to a lesser extent just walking, cause inflammation. While this type of inflammation is good and necessary, you can overdo it. Inflammation binds water, increasing weight, masking fat loss, and generally makes life quite un-fun. Moving less can give your body time to relax, rebuild and restore, calming down to make progress again.

As you surely noticed, the strategies to keep losing weight are sometimes contradicting. This means that you have to find out what exactly your problem is and which of these strategies can help to make progress again. Sometimes this simply is a matter of trial and error, so be patient.


Metabolic damage really is a myth. You can not permanently damage your metabolism, but our body is able to modulate or metabolism recording to energy availability. This is called metabolic adaptation and is completely normal and reversable.

Weight loss plateaus are completely normal and are simply the product of metabolic adaptation, underreporting and/or overestimating activity.

Weight loss plateaus can be broken by manipulating energy consumption and movement. Different strategies are useful for different people.

Are you struggling with a boring diet or are you not enjoying your training anymore? Contact us and let us talk how we can reach your body composition or strength goals and let training and eating be fun again!

Success! You're on the list.

One thought on “The Metabolic Damage Myth”

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: