Elevate Your Fitness, Elevate Your Life

Call Today


Will Taking Amino Acids Break Your Fast?

Will Taking an Amino Acid Supplement Break Your Fast?

Technically, taking an amino acid supplement such as essential amino acids (EAAs) or branched-chain amino acids (BCAA) will break your fast. However, you still might want to take them while fasting.

Amino acids are the building blocks of proteins. They are molecules that combine to form proteins. We all need to eat and consume the nine essential amino acids for good health. 

There are essential and nonessential amino acids. The body can make nonessential amino acids even if you don’t get them from food, but you have to eat or take a supplement to get the nine essential amino acids. Out of the nine essential amino acids, three are considered the BCAAs. 

BCAAs became very popular in the bodybuilding 💪 and fitness world many years ago because they are high in muscle signaling and building amino acid leucine. But recent research has shown that you need all the nine essential amino acids (not just three) in reasonable quantities for protein synthesis (muscle building) to occur. 


The essential amino acids and BCAAs include:

  • Histidine
  • Isoleucine (BCAA)
  • Leucine (BCAA)
  • Lysine
  • Methionine
  • Phenylalanine
  • Threonine
  • Tryptophan
  • Valine (BCAA)

The nonessential amino acids are:

  • Alanine
  • Arginine
  • Asparagine
  • Aspartic acid
  • Cysteine
  • Glutamic acid
  • Glutamine
  • Glycine
  • Proline
  • Serine
  • Tyrosine

I know it can be confusing when you look at the back of an amino acid supplement, and you see no calories, but there are calories in amino acids. The rules for posting calories in a supplement states that it has to be a complete protein. Since amino acids are individual molecules, supplement companies don’t have to report the calories (some report the calories). 

So, yes, taking an amino acid supplement will slightly break your fast because they have calories. You have to determine what your goals are for fasting. If your goal is to reduce body fat, keep insulin levels low and maintain or put on muscle mass, it might be a good idea to take some EAAs while fasting. It will give you a minimal spike in insulin, and it can help you maintain and put on muscle. 

On the other hand, if you are mainly fasting for autophagy, the recycling of weak and damaged organelles, you might lose some benefits if you take amino acids. Because leucine is a growth signaling amino acid, it activates mTOR and IGF-1, which puts you in an anabolic state (building and maintaining your muscle mass) instead of a fasting state when you are breaking down and repairing. 

I sometimes like to take EAAs when I’m fasting or doing a fasted workout to ensure getting amino acids with very few calories and a minimal spike in insulin. I do feel that it helps me maintain and put on muscle.

Best – Mike Cola

You May Also Like…

Meals For Fat Loss

Meals For Fat Loss

Designing your meals for fat loss can be simple if you follow the three steps outlined in this article. Losing body...