Proteins are essential for the growth, maintenance, and repair of all your cells and tissues. Proteins are found in every cell of your body and are the main building blocks of life. They're made up of strings of amino acids like pearls on a necklace and they perform many vital functions in your body to help keep you healthy.
Proteins play many different roles. Some act as enzymes, speeding up chemical reactions. Some provide structure, such as the collagen in your skin, connective tissue, and bones. Some work as hormones, carrying messages from one part of the body to another. Some work in the immune system as antibodies, protecting you against pathogens. While others act as carriers, transporting things to your cells, such as oxygen-carrying hemoglobin.
There are 20 different amino acids required by your body. Eleven are considered non-essential, because your body is able to make them. However, there are nine amino acids that your body cannot produce, so you must get them from the foods you eat.
The essential amino acids include:
- Histidine
- Isoleucine
- Leucine
- Lysine
- Methionine
- Phenylalanine
- Threonine
- Tryptophan
- Valine
All animal foods, including meat, poultry, fish, dairy, and eggs, contain all nine essential amino acids and are considered to be complete proteins. However, protein can be found in almost every food in varying amounts, except for fats and oils. So it is possible to meet all your protein needs without eating animal products.
However, when omitting animal products from your diet, it is extremely important to ensure that you are supplementing your diet with vitamin B12, an essential B vitamin found only in animal foods.
Although animal foods conveniently contain complete proteins, combining incomplete plant-based foods in a way that create complete proteins can meet your daily protein requirements.
The following plant food combinations make complete proteins:
- grains + legumes (e.g., black beans and wild rice)
- grains + nuts or seeds (e.g., sprouted grain bread with nut butter)
- legumes + nuts or seeds (e.g., chickpeas and sesame seed paste = hummus)
Including these combinations in your daily meal plans should allow you to meet your daily protein requirements. There are also a few superfood plant sources that contain all nine essential amino acids which can make things a little easier.
Plant foods that contain all 9 amino acids include:
- buckwheat
- hemp seeds
- quinoa
- fermented soy (such as tempeh)
Unlike carbohydrates and fats, we don’t have a specialized place in our bodies to store proteins for later use, so it’s important to eat a good balance of protein-containing foods daily.
Most plant foods contain some protein (various amino acids) in varying amounts, so most of us usually don’t have to worry about getting enough protein in our diets, even without eating animal foods at every meal.