Do Amino Acids Make You Gain Weight
Amino acids typically do not cause weight gain as long as you are not consuming more calories than your body uses for energy

Amino acids typically do not cause weight gain, even though there are 4 calories per gram, which is equal to the amount of glucose in one gram of table sugar. Unlike glucose, your body does not store amino acids but instead absorbs them, which are then used by your muscles.

Even if you increase your intake of amino acids, your body absorbs only small amounts and the rest is eliminated through waste. However, consuming high amounts of amino acids can cause weight gain if you are consuming more calories than your body uses for energy.

Instead of worrying about gaining weight from amino acids, practice moderation and eat a balanced diet while staying within your calorie limits.

What are amino acids?

Amino acids are considered the building blocks of proteins because they are small molecules that combine to form protein. Although your body naturally produces various amino acids, others cannot be produced on its own.

Thousands of proteins in your body are formed from 20 amino acids:

  1. Alanine
  2. Arginine
  3. Asparagine
  4. Aspartic acid
  5. Cysteine
  6. Glutamic acid
  7. Glutamine
  8. Glycine
  9. Histidine
  10. Isoleucine
  11. Leucine
  12. Lysine
  13. Methionine
  14. Phenylalanine
  15. Proline
  16. Serine
  17. Threonine
  18. Tryptophan
  19. Tyrosine
  20. Valine

Essential amino acids

Out of the 20 amino acids, 9 cannot be synthesized in your body and must be obtained through food. These are called essential or indispensable amino acids:

  1. Histidine
  2. Isoleucine
  3. Leucine
  4. Lysine
  5. Methionine
  6. Phenylalanine
  7. Threonine
  8. Tryptophan
  9. Valine

The 9 essential amino acids are the only required ones for most physiological states in a healthy adult. Amino acids such as arginine and histidine, however, could be considered conditionally required because the body cannot synthesize them in sufficient quantities during certain stages of growth, such as pregnancy, puberty, or trauma repair.

Nonessential amino acids

The other 11 out of 20 amino acids that can be synthesized by the body are considered nonessential amino acids.  However, you may need nonessential amino acids in food supplements to repair body tissues following trauma.

What are daily protein requirements?

The Dietary Reference Intake (DRI) report for macronutrients states that a sedentary adult should consume 0.36 grams of protein per pound of body weight.

This means the average sedentary man should consume approximately 56 grams of protein a day, whereas the average woman should consume approximately 46 grams a day.

Protein should account for 10%-35% of your total caloric intake. So if your body requires 2,000 calories per day, 200-700 of those calories should be from protein. If you burn more calories with exercise, you can increase your protein intake through food or protein supplements.

Examples of protein-rich foods include:

  • Meat
  • Soy
  • Egg whites
  • Nuts
  • Seeds
  • Whole grains
  • Beans
  • Lentils
  • Chickpeas
  • Skinless, white-meat chicken or turkey
  • Lean cuts of beef or pork
  • Low-fat dairy
  • Fruits
  • Vegetables
  • Whey protein

What are side effects of taking too many amino acids?

If you consume excessive amounts of amino acids, side effects may occur:

Before increasing your protein consumption or deciding to take protein or amino acid supplements, talk to your doctor.


According to the USDA, there is no difference between a “portion” and a “serving.” See Answer

Risks associated with consuming too much protein

Weight gain

Eating too much protein can cause your body to convert the excess protein to sugar, which is then stored as fat. Increasing your protein intake also means increasing your overall calorie intake, so you would need to reduce your intake of other macronutrients in order to prevent weight gain.

Kidney dysfunction

If you have kidney disease, eating too much protein can be harmful. When your body recognizes the need to remove nitrogen components from excess protein to store it as energy, this increases the production of ammonia. Ammonia is subsequently converted to urea by the liver and released into the bloodstream. This can put strain on your kidneys, who will need to work overtime to eliminate organic waste from the bloodstream and excrete urea through urine.

If you have preexisting renal problems, consult your doctor before increasing your usual protein consumption.


Water and other fluids are needed to flush out excess nitrogen found in protein in the body, which can lead to dehydration. When your body isn’t getting enough carbohydrates, it begins to deplete stored glycogen molecules for energy. This hinders the ability to store water in the body and can lead to water electrolyte imbalance. 

So if you are increasing your protein intake and restricting your carb intake, it is important to stay adequately hydrated.

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Medically Reviewed on 2/3/2022
Image Source: iStock Images

Khan Academy. Introduction to proteins and amino acids.

Harvard T.H. Chan. Protein.