Proteins are, after water, the most abundant substance in the entire body. Proteins are made of long chains of amino acids. Amino acids are crucial for every metabolic process in the body. There are 22 amino acids in total and all of them are important. Humans can produce 10 out of the 22 amino acids – the remaining 12 must be supplied through the food we consume.
Protein is a key molecule found in every single cell of the body.
Proteins are divided into two main groups: complete proteins and plant proteins. Being a huge part of all our body’s cells, proteins make sure everything functions optimally, and help with growth, maintenance, and repair of tissue. Proteins transport messages between cells, keep our immune system strong, regulate organ function, and so much more.
We have to consume two or three small portions of protein every day. As long as we provide our body with the recommended daily amount, our cells don’t mind if the proteins are complex or plant-based.
The daily recommended amount of protein is different for every body, and the amount depends largely on your lifestyle. The more active you are, the more protein your body requires. Generally it should be calculated in the following way:
0.8 grams of protein per kilogram of body weight, or 0.36 grams per pound. This amounts to: 56 grams per day for the average sedentary man and 46 grams per day for the average sedentary woman.
Complete vs Incomplete Protein Sources
Your body needs 22 different types of amino acids to function properly. Adults can synthesize 13 of those within the body (known as non-essential amino acids), but the other 9 must be obtained from food (known as essential amino acids). It’s these essential amino acids that derive the classification of protein as either complete or incomplete.2
Complete Protein Sources
Complete proteins are those that contain all essential amino acids in sufficient quantity – these are typically animal-based proteins, but a few plant sources are also considered complete. A few examples:
- Meat
- Fish
- Dairy products (milk, yogurt, whey)
- Eggs
- Quinoa*
- Buckwheat*
- Hemp and chia seed*
- Spirulina*
Incomplete Protein Sources
Incomplete proteins are those that don’t contain all 9 essential amino acids, or don’t have sufficient quantities of them to meet the body’s needs, and must be supplemented with other proteins. These include:
- Nuts & seeds
- Legumes
- Grains
- Vegetables
Just because they are incomplete doesn’t make them inferior, though, they just need to be combined to provide the right balance of essential aminos. Proteins that, in combination, make a complete amino acid profile are known as complementary proteins.
- Rice and beans
- Spinach salad with almonds
- Hummus and whole-grain pitas
- Whole-grain noodles with peanut sauce
Complementary proteins don’t necessarily need to be eaten together, but since your body doesn’t store amino acids for later use in protein combining, they should be eaten throughout a day’s meals.