Tip: Strict Diets vs. Your Metabolism

Here's what you need to know about rigid eating plans, adaptive thermogenesis, and metabolic compensation.

Can You "Break" Your Metabolism?

Some people say that a really strict diet – like one you do to get ready for a bodybuilding show – will wreck the metabolism. Will it?

Well, it probably won't... at least not in the way most seem to think. There are definitely some issues you can induce with extreme dieting and exercise, but "wreck" is probably too strong a term. That assumes you broke something. The metabolism doesn't break. In fact, it's doing exactly what it's designed to do.

Let's get some definitions out of the way, because that's where most of the confusion starts. You've likely heard of the admittedly vague and non-medical terms like "adrenal fatigue," "starvation mode," and "metabolic damage." These are more marketing lingo than medical terminology. But that doesn't mean they don't have some utility.

In medicine there's often dysfunction before disease. For example, if you have a fasting blood sugar level above 126 on two separate occasions, then I can diagnose you with diabetes.

However, if you have a blood sugar above 100 but below 125, what do I call that? You don't yet have diabetes, but you obviously have some dysfunction. We call these a lot of different things in medicine: prediabetes, dysglycemia, impaired glucose tolerance, or something else.

Same thing with the metabolism. When you have difficulty sleeping, insatiable hunger, unstable mood, unpredictable energy, uncontrollable cravings, and you're no longer responding to the same calorie deficit BUT your blood labs and vitals are all normal, what do we call that?

There's obviously something going on, but we can't put a diagnosis on it, can we?

So, we use some descriptive terms like metabolic compensation, metabolic resistance, metabolic dysfunction, or metabolic damage. Or like you, we just say, "Damn, I think I wrecked my metabolism!"

You didn't. What happened is a predictable phenomenon and we know some (although not all) of what it's about. Part of it is what research calls "adaptive thermogenesis."

A competition diet is well-known for inducing a very wide calorie cap. You cut calories down and you expend a lot of energy through weight training and/or cardio. In the same way not changing your car's oil or filling up with gas will cause the engine to conk out, the body does not respond well to this large energy discrepancy.

In response it will increase hunger, reduce motivation, lower energy and (most insidiously) decrease its metabolic output. It does that in many ways:

  • It reduces resting energy expenditure through downward regulation of thyroid and other hormones.
  • It increases hunger and cravings.
  • It sneakily causes you to move around less the rest of the day. If you normally get up and walk around 100 times per day you'll find that it's now only happening 25 times per day. If you move in your sleep that will stop as well. You'll also burn less during exercise, something research calls "constrained caloric burn."

What's worse, after the show, when you no-longer have the external motivator and would prefer to eat like a human being, you're primed to gain all that weight back plus some.

I've come to call this the "metabolic credit card effect" –– you get short-term results, but you pay steep metabolic penalties later. Anyone that's seen a first-time figure competitor blow up like a helium balloon post competition knows this well.

Is that a wrecked metabolism? I suppose you could describe it that way, but another way to look at it is your metabolism is doing just what it's designed to do. It feels it needs to recover that debt. After all, it evolved in a feast and famine reality and it thinks it's doing you a favor by mitigating the famine and maximizing the feast.


The good news is there are some ways to reduce metabolic compensation. Here are some things to do:

  1. Do your best to maintain as much muscle as you can. The metabolic rate will not slow as much and be more resistance to fat regain. This means to make weight lifting the dominant part of your fitness regime during fat loss.
  2. Cardio becomes a little more important after weight loss, when the metabolic rate has lessened. You may want to save your cardio for after, rather than during the competition diet.
  3. Eat more protein, see the first point above about maintaining muscle mass. And probably increase the amount of protein as a percent of total calories. Do this during, but perhaps more importantly, after fat loss.
  4. Cycle the calorie gap, having times where you're in a strong deficit and other times where you're in no deficit at all. The recent MATADOR study (minimizing adaptive thermogenesis and deactivating obesity rebound) showed this strategy got better results, had less metabolic adaptation, and much longer lasting results.
  5. Don't eat like an asshole when it all ends. Focus on blander foods and less variety of them. Doing the traditional burger, pizza, and cheesecake binges will trigger the brain's hedonistic response and cause you to want more of that same dopamine hit – all this when the metabolism is at its most vulnerable in terms of fat storage.
  6. And finally you may want to consider some type of adaptogen like rhodiola or ashwagandha. I have no studies to back this up, but I have very good success clinically with using these herbs along with the recommendations above to keep the command and control center of the metabolism (the brain's hypothalamus) stress-resistant and happy.