How Do BCAAs Have No Calories?

They’re essential for muscle growth, but how do BCAAs have no calories?

This was a question I received from website member Alex, who was thinking about using a BCAA supplement during his intermittent fasting window.

If you flip your tub of BCAAs around to view the nutritional information, you’ll likely see the same thing; zero calories!

how do bcaas have no calories

How Do BCAAs Have No Calories?

No, there’s no voodoo at work here.

The reason BCAAs have no calories is not so much ‘magic’, more a loophole in supplement industry regulations.

You see, a supplement manufacturer is not allowed to list the calorie content of a food/supplement which contains only free form amino acids.

“Protein shall not be declared on labels of products that, other than ingredients added solely for technological reasons, contain only individual amino acids.”

Current FDA Guidelines

BCAA supplements do contain calories, but they’re not allowed to list them because in their individual form they don’t make up a complete protein.

What This Means For You

In their free form state, they contain largely the same amount of calories as when they combine to form protein.

The branch chain amino acids (leucine, isoleucine and valine) provide around 4.6 calories per gram. (1)

We can use this information to debunk a few of the most common BCAA myths and keep you on the right track.

1. Can You Drink BCAAs Without Gaining Weight?

BCAAs contain calories, so no.

2. Can You Drink BCAAs During Intermittent Fasting?

Muscle building magazines regularly advise us to drink BCAAs during our fasting window in order to prevent muscle breakdown and fight off fatigue. (2)

This is BS advice.

First off, you’d need to be attempting the training routine of a damn Olympian to even be concerned with muscle breakdown. (3)

Second, they will also break your fast. Because calories.

3. Should You Take BCAAs Before Fasted Cardio?

“Do 45 minutes of early morning fasted cardio, bro. Be sure to take your BCAAs beforehand, to prevent muscle loss!”

I’m sure you’ve seen or heard this advice before.

Although any potential muscle loss would be minuscule, and BCAAs would indeed prevent this from happening, the answer lies within the question above. Because the calories in those BCAAs would mean you are not actually performing fasted cardio anyway.

So next time you see a BCAA supplement, or hear a gym bro saying “BCAAs have no calories”, now you know the facts. If industry regulations change at any point, I will update this content.

how do bcaas have no calories


  1. May, M. E., et al. Energy content of diets of variable amino acid composition. Am J Clin Nutr. (1990)
  2. Portier, H., et al. Effects of branched-chain amino acids supplementation on physiological and psychological performance during an offshore sailing race. Eur J Appl Physiol. (2008)
  3. Borgenvik, M., et al. Intake of branched-chain amino acids influences the levels of MAFbx mRNA and MuRF-1 total protein in resting and exercising human muscle. Am J Physiol Endo Metab. (2011)

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