Proteins are truly amazing nutrients because they are involved in just about everything that happens to your body. About 15% of your body is made up of protein, most of which is in your muscles. However, there are different types of proteins throughout the body, such as enzymes, hormones, immune factors, and blood-clotting factors. Proteins also help regulate fluid balance (how much water your body stores), your ability to see, and your acid-base balance (the pH of your blood). They also provide energy when necessary at 4 calories per gram. See, we told you they were important!

Protein sources

Nearly all animal foods, such as meat, dairy products, eggs, and fish, are concentrated sources of protein because they typically contain all 9 essential amino acids. However, some animal protein sources are also high in saturated fat, which can raise cholesterol levels, so you have to choose wisely.

An often overlooked source of protein is plant foods. Specifically nuts, seeds, beans, and peas can be terrific sources of protein. One thing to keep in mind with plant sources of protein, especially if you’re eating a vegan diet (no animal foods whatsoever), is that not all plant proteins are equal. Plant foods tend to have lower levels of certain essential amino acids compared with animal foods, but certain plant foods complement each other with their amino acid profiles. For example, beans tend to be low in one amino acid that grains are high in, so combining these foods helps to form a more complete protein. Although ideal, combining these foods in the same meal isn’t necessary to ensure you meet your protein needs. If you eat a wide variety of plant foods and meet your calorie needs, getting enough protein is rarely an issue.

Nowadays there are numerous meat and dairy substitutes that are delicious and have plenty of high-quality protein. Be adventurous and try the wide variety of veggie burgers, veggie dogs, veggie deli-slices, alternative milks (like soy milk), and other products now widely available.

Amino acids

Protein is made up of individual building blocks called amino acids. There are 20 different amino acids the body uses to make various proteins. However, the body itself can make about 11 of these amino acids, leaving 9 that we must get from food. These remaining 9 are called essential amino acids, meaning it is essential that we get them from our diet.

Calling amino acids the building blocks of proteins is an understatement. Your body arranges the 20 different amino acids in an almost infinite number of configurations to form proteins. It's the configuration that ultimately determines the role and function of each protein. And if the amino acids are arranged incorrectly, it may mean the difference between health and disease. For example, sickle cell anemia results from just one single wrong amino acid being used to make hemoglobin. Okay, now that you get how important they are, where do you get them?

How much protein should you eat?

The amount of protein needed per day differs from person to person. For healthy adults, the Institute of Medicine publishes a report — the Dietary Reference Intakes Report — that recommends a range of protein between 10 and 35% of calories. For a 2,000-calorie diet, that would mean consuming between 50 and 175 grams of protein. The reason for the wide variability in protein allowance is that research indicates a healthy diet can be achieved consuming levels anywhere within this range. Your goals, personal preferences, and lifestyle choices can dictate where your protein intake should fall. As long as your protein choices come from lean sources and/or plant sources (so that your intake of saturated fat isn’t too high), consuming more protein than had been previously recommended can be considered part of a healthy diet.