Proteins are made from 20+ basic building blocks called amino acids. Protein is essential for your body to grow and repair the cells and to work properly. Since our bodies don’t store the amino acids, these are made in two ways: by modifying others or creating from scratch. Although the amount of protein needed from your diet depends on the weight, age, gender and health, the average intake of protein is calculated to be around 0.8 grams for every kilogram of body weight per day as per different sources. The various parts of the body where proteins are found are muscle, skin, bone, hair, and almost every other body part or tissue.
There are some amino acids which can be made by our body which are also known as non-essential amino acids (11 in number). There are 9 amino acids which our body can not make – histidine, isoleucine, methionine, leucine, lysine, phenylalanine, tryptophan, threonine, and valine – these must come from food. The amount of essential amino acids is the measurement of nutritional value of a protein.
Foods shown below with essential amino acids:
- Animal products (eg. chicken, fish, beef or and dairy products) consists of the essential amino acids and also known as ‘complete’ protein.
- Quinoa, Soy products, and the seed of a leafy green called amaranth consist of essential amino acids.
- Plant proteins (beans, nuts, lentils, and whole grains) usually lack at least one of the essential amino acids that’s why considered as ‘incomplete’ proteins.
Few examples of protein sources:
- lean meats – beef, veal, lamb, pork
- fish and seafood – fish, crab, prawns, lobster, oysters, mussels, scallops
- poultry – chicken, duck, turkey, emu, bush birds goose,
- nuts and seeds – almonds, walnuts, pine nuts, macadamias, cashews, hazelnuts, sesame seeds, pumpkin seeds, sunflower seeds
- dairy products – milk, cheese (esp. cottage cheese), yoghurt (esp. Greek yoghurt),
- legumes and beans – all beans, chickpeas, lentils, split peas, tofu.
Although there are other cereal-based and grain products, these products have less protein compared to meat or other high protein foods.