Types of proteins, incomplete protein vs complete protein.

Protein is one of the three macronutrients that your body needs, as well as the main source of amino acids for your body. These amino acids allow your body to perform many of its functions such as muscle building, sleep and digestion regulation, etc. But not all the food contains the same amount of amino acids. Thus, people often talk about two types of proteins, incomplete proteins and complete proteins.

How does your body gets amino acids?

The same way it obtains energy from carbohydrates or fats, through DIGESTION. Think about food as a knot of twisted threads, each one being an amino acid, when your body digests the food it unties the knot and gets access to the threads.

However, there is another source of amino acids, itself. Although amino acids can be found in food, they can be synthesized by your body. So, why bother? Turns out your body needs around 20 (twenty) different amino acids, but can only synthesize 13 (thirteen). Therefore, the other ones must be acquired through eating.

As a consequence of this, we get two categories of amino acids: non-essential (which your body can make on its own) and essential ones (that can only be found in food).

Essential amino acids

All amino acids

  • Alanine
  • Arginine
  • Asparagine
  • Aspartic acid
  • Cysteine
  • Glutamine
  • Glutamic acid
  • Glycine
  • Histidine
  • Isoleucine
  • Leucine
  • Lysine
  • Methionine
  • Phenylalanine
  • Proline
  • Serine
  • Threonine
  • Tryptophan
  • Tyrosine
  • Valine

Essential amino acids.

  • Histidine
  • Isoleucine
  • Leucine
  • Lysine
  • Methionine
  • Phenylalanine
  • Threonine
  • Tryptophan
  • Valine

 

All foods which contain protein have every essential amino acid but not in the same amount. This in term classifies them as complete proteins (if they contain the sufficient amount for your body) or incomplete proteins (if they are lacking enough of one or more essential amino acids).

What foods contain complete proteins?

Meats (chicken, pork, beef), fish, eggs, dairy, quinoa, soy.

What foods contain incomplete proteins?

Vegetables, legumes, fruits, and nuts.

What does this mean?

Well, you should aim to ingest a decent amount of all amino acids by consuming at least one or two sources of complete protein a day. Not because is the only way, but because this is the easier way. If you are not into meat and dairy, you can consume complementary foods by looking which amino acid is lacking in one and eating another with more of it.

For example, lentils have a low content of methionine, so if you are having lentils, try and eat brazil nuts, or parmesan cheese as a complementary food. (these last ones have a high amount of methionine)

Finally, I’d like to add, DON’T STRESS trying to get all 20ish amino acids in your meals for a day, your body stores some for these emergency cases, and consuming a low amount on one of them for a day shouldn’t be a major issue for healthy people.