Will strict diets wreck your metabolism? Can you boost testosterone via diet? And how do you build muscle without getting fat? Answers here!
Q: Some people say really strict diets – like the ones you do for bodybuilding competition prep – will wreck your metabolism. Is that true? And if so, how do you fix this issue?
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 with these types of discussions. 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:
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
Q: Is there a way to boost testosterone, or at least optimize it, via diet alone? And are there foods or diets that decrease T?
You can think of testosterone like a sex and reproduction barometer. It’s partly responding to the environmental inputs.
When it comes to diet, the question is: Is there enough food to drive metabolic demand? Not too little and not too much? If so, bring on the T!
The metabolism wants the “goldilocks effect” when it comes to testosterone. This is why fat couch potatoes and gaunt, thin-skin bodybuilders have no motivation, no desire for sex, and soft, non-responsive or less reliable erections.
So, the first thing to remember is, don’t go too low for too long in any one of the macronutrients (protein, carbs, and fats). That can be a T killer. The second thing is to balance training with recovery.
But your question is a nuanced one, and I don’t want to come down too hard on any one dietary practice. I’ve seen slightly overweight individuals go on keto diets and measure notable positive changes in T levels. I’ve seen that same diet cause issues in libido, muscle gains, and erections. The discrepancy is explained by the individual.
If I had to give a general rule of thumb (which is usually dangerous and stupid), I’d say…
- Don’t go below 20% fat.
- Don’t go below 30% carbs.
- Keep your protein above 20%.
A 40-30-30 (carbs-protein-fat) ratio if you’re trying to gain muscle or compete in a sport is great. A 30-40-30 macronutrient ratio if you’re wanting to lose fat is good for most.
Oh, and some studies suggest that if you’re low in magnesium, zinc, or vitamin D you may get a T boost from supplementation. ZMA along with appropriate sun exposure and 2000-5000 IU vitamin D daily (take with your biggest meal) may be some good insurance.
So to repeat…
- Stay away from extremes in leanness and extremes in fatness.
- Stay away from extreme macronutrient and calorie imbalances.
- Train enough, but not too much.
If your T is optimized, you should feel it. Your brain will be focused and driven. Your exercise performance and recovery will be on point. You’ll be lean and feel fit. And your penis will be responsive, recharged, and resilient.
Q: How do I increase muscle but not body fat? I typically get too fat when eating for mass. How many calories over maintenance are really needed to optimize muscle gains?
The metabolism is not a great multitasker. It likes to be building up fat and muscle (anabolism) or tearing them both down (catabolism). Trying to do both at once is the metabolic equivalent of patting your head and rubbing your belly. You can do it, it’s just not that easy… unless you’re a beginner or using anabolics.
The trick here is to understand you have four different metabolic toggles to pull:
This will burn fat and muscle because it creates a pretty intense and wide calorie gap through both exercise and food. Think marathon runner or skinny fat.
This will put on both muscle and fat through creating a calorie gap in the other direction. Think powerlifter or muscle-fat.
That latter scenario is what most people try to do when they want to gain muscle. It works, but it often makes you look like you just put a jacket on top of two sweaters. It’s not the best approach or the best look. This is usually creating a 500-calorie surplus or more, and that may be too much if the training isn’t right.
Think the little old lady in Paris who climbs four flights of stairs six times a day, but eats only half a baguette, a cup each of coffee and wine, a radish, and some cheese. She stays lean because she drives the calorie deficit through diet and moves enough to not become a skeleton. This protocol is obviously not for you.
That’s the toggle you want. It’s the athlete toggle. Ramp up your food intake to a slight surplus so you can gain some muscle. I suggest somewhere between 15 and 20 times body weight in pounds depending on whether or not you’re a hard gainer. You sound like you tend to get “muscle-fat” easily (same as me), so you should stay near 15 to start.
Now set your macronutrients to 40-30-30 (carbs, protein, and fat). You’ll need the extra carbs. Insulin is, after all, the most powerful anabolic hormone in the body. If you can’t get that fuel in the cell, you’re not going to grow no matter how much testosterone you have.
Now turn on the training intensity like you’re a banshee in a bench, squat, and deadlift competition to the death. Doing things this way will amplify energy flux, reduce fat (or at least minimize its accumulation) and put mechanical pressure on the muscle to grow.
If it’s not working, SLOWLY ramp up the calories until it does. My guess is you’ll end up in a slight surplus of 200-400 calories. This is the best way to multitask.