Muscle burns more calories than fat, right?
It certainly doesn’t on my body.
When I started strength training and added lots of muscle to my frame, my metabolism ended up slower than it was when I was fat an out of shape. That may seem like a weird claim, but let me explain.
I’m sure you’ve heard the idea that muscle burns more calories than fat before; it’s one of the much-touted myths that the fitness industry like to trot out on a regular basis to win people over.
But depending on how it’s stated, the claim is either technically true but still an exaggeration, but merely a complete falsehood.
Can all those fitness books and Youtube gurus be wrong?
I’ve read a lot of fitness and weight loss books over the years, and most of them mention – or even base their plans on – the idea that strength training will increase your metabolic rate by piling muscle on your body.
Sure, your metabolism will slow down if you shed body fat, the thinking goes, but you just need to add a few pounds of lean mass to more than make up for it. Most will tell you that a single pound of muscle adds (depending on the author) 50 to 100 calories a day to your basal metabolic rate.
That sounds great! Even just a few pounds of lean mass would turn you into an energy-burning machine. Add a few more and you’ll be able to scarf down all the donuts you want without having to worry about body fat.
But is it true? Despite quite a bit of searching, I’ve never found a scrap of evidence put out a legitimate researcher publishing in a peer-reviewed journal that could support a muscle caloric burn figure anywhere near 50 calories per pound, much less the 70 to 100 calorie BMR boost some youtube gurus claim.
Actually, all the evidence supports a dramatically lower figure.
The Muscle BMR Reality
It turns out that while muscle burns more calories than fat, it’s not a lot more.
Unfortunately, the most metabolic “expensive” tissue in your body doesn’t grow a whole lot1. The heart and kidneys churn through 200 calories per pound per day, and the brain clocks in at 109. Even the liver manages a respectable 91 calories per pound per day.
But muscle? It only burns 6 calories per pound per day, which isn’t a whole lot more than fat, which burns 2 calories.
Even when they’re touting the health benefits of muscle, experts like Dr. Robert Wolfe, Chief of Metabolism and Professor of Biochemistry at the University of Texas Medical Branch, won’t claim a metabolic miracle will occur if you add some lean mass.
His research indicates you can add 5 calories a day to your BMR by adding a pound of muscle2, which is even less than the 6 calorie-figure I cited above.
Muscle Burns More Calories Than Fat? Let’s Do The Math
So let’s get back to me.
I used to be obese, weighing in at 220 pounds. Over a number of years I gradually improved my diet and started doing endurance training, and I dropped to 158 pounds, for a total loss of 62 pounds of fat loss. This means that my basal metabolic rate slowed by 124 calories.
In 2011 I got tired of being scrawny, and was generally bored with the endurance training, and I started strength training instead. After quickly putting on some muscle, I changed my training regimen to limit muscle gain while still increasing strength gain, since I have no desire to slow myself down more than necessary.
Even so, today I weigh 170 pounds, or 12 pounds more than when I was sticking to endurance training. That means that my new muscle mass increased my basal metabolic rate by 72 calories, which isn’t even close to replacing the 124 calories of BMR I lost when I shed all that fat.
Yes, an already lean person who added 12 pounds of muscle without losing fat would start burning a bit more per day, but adding 72 calories per day wouldn’t even cover the energy cost of a 7-inch banana, so it’s not really a bit deal.
Be Smart And Strength Train Anyway
So yes, muscle burns more calories than fat, but it’s not a significant enough difference to really matter much.
All the same, you should still do progressive resistance training of some type. Not only do you look better with more muscle on your body, if you’re shedding bodyfat at the same time, doing resistance training will stop your body from burning through your existing muscle when you run a calorie deficit.
If it’s fat loss you want, then be smart and make the basis of your efforts a healthy diet. My book, Raw Food Weight Loss And Vitality, is a great first place to start.
Wang, Z., Heshka, S., Zhang, K., Boozer, C.N., & Heymsfield, S.B. (2001). Resting energy expenditure: systematic organization and critique of prediction methods. Obesity Research, 9, 331-336.↩
Wolfe RR. (2006). The underappreciated role of muscle in health and disease. American Journal of Clinical Nutrition, 84, 475-482↩