Complete vs. Incomplete Proteins
Of the 20 amino acids that our body needs to fuction, 9 of them are essential. This means that they are not produced by our bodies and therefore must be consumed in the diet. A complete protein is one that contains all 9 essential amino acids in sufficient amounts. An incomplete protein is one that either lacks one or more of the 9 essential amino acids or doesn’t make enough of one to be completely functional on its own.
In general, all animal sources of protein, including meats, dairy, fish and eggs are complete proteins (except gelatin). The egg white is considered the golden standard for a complete protein.
Plant sources of proteins, including fruits, veggies, grains, nuts, and legumes provide incomplete proteins. Soy is an exception to this rule and is actually a complete plant protein.
Not a meat eater? Don’t despair! While each plant protein on its own is incomplete, when they are paired with a complementary protein, the proteins make up for what each other lacks. It is good to eat complementary proteins together but if you can’t it is generally considered effective to eat them within 2 meal periods of each other.
Here is a general guide to creating complete proteins from plant sources:
- Grains + Legumes = Complete Protein (e.g. peanut butter on whole grain toast)
- Grains + Veggies= Complete Protein (e.g. brown rice and broccoli)
- Veggies + Nuts= Complete Protein (e.g. green beans with almond slices)
- Legumes + Nuts = Complete Protein (e.g. vegetarian chili with cashews)