Everything You Need to Know About Protein


Along with carbohydrates and fat, protein helps your body produce amino acids, the building blocks of lean muscle. Regardless of your fitness goals, you won’t reach them if protein isn’t a major part of your regular diet.


Protein builds, maintains and restores muscle. It's responsible for healthy blood cells, key enzymes and strengthening the immune system. 


In order to build muscle, protein must be consumed with enough carbohydrate calories to provide the body with energy. Otherwise your body will tap into the protein for energy. And if you're avoiding saturated fats, you'll want to avoid certain forms of animal proteins such as heavily marbled beef.


Because it is often recommended to eat protein frequently throughout the day, you might think this means you have to eat beef several times a day, but that's not the case. Here is a short list of plant and animal protein sources:

Animal Protein

  • Fish (anchovies, calamari, cod, flounder, grouper, halibut, mackerel, mahi mahi, salmon, sardines, swordfish, tuna canned in water, tuna steak, sushi)
  • Shellfish (clams/mussels, crab, lobster, oysters, shrimp/prawn)
  • Poultry and other meat (chicken, turkey, buffalo, filet mignon, flank steak, lean ground beef, fat-free ham, London broil, lean pork loin, top and bottom round of beef, venison
  • Dairy (milk, cottage cheese, yogurt, cheese)
  • Eggs
  • Supplements (whey, casein)

Plant Protein

  • Legumes (beans, peas, lentils, soybeans)
  • Vegetables
  • Grains
  • Cereals
  • Nuts & seeds


Whey protein contains many essential amino acids that boost the immune system and promote overall good health. You can find it in dairy foods, but also as a supplement in powdered form or in pre-made post-workout recovery mixes. The flavored powder tastes great sprinkled on oatmeal or mixed with milk, water or juice.

Whey is quickly digested, which makes it great for eating around workouts. Many protein shakes combine whey protein with another type of slow-releasing protein, casein. This mixture provides a combination of fast and slow releasing proteins, which allows for complete coverage over two-and-a-half to three hour window between meals.

Protein shakes with some additional carbohydrate accelerate workout recovery. You can buy shakes in a ready-to-drink container, or easily make them yourself by mixing water with a scoop or packet of powder, so they’re a quick and easy snack that's rich in protein but low in of bad fats.

Whey vs Casein

Most protein supplements are made from either whey protein, casein protein, or a mixture of the two. The major difference between these two milk proteins is the rate of absorption:

  • Whey protein is rapidly absorbed helping to induce muscle-protein synthesis following a training session.
  • Casein protein is slowly absorbed providing a long steady flow of amino acids, helping to prevent muscle-protein degradation.

Post-training supplements containing a mixture of both fast and slow proteins are superior to their individual counterparts because they not only induce muscle-protein synthesis but they also help to prevent muscle-protein degradation.

Protein Quality

It is important to choose low fat protein sources, or protein sources that contain healthier fats (e.g. nuts, seeds, fish)

  • Fish is a tremendously healthy source of protein. Fish also provides omega-3 and omega-6 fatty acids, which promote cardiovascular health. Shellfish (crab, lobster shrimp and prawns) is the exception to this rule.
  • Chicken is also a wonderful source of protein.
  • Beef and other red meats can be good, too, provided cuts are lean—that’s the key distinction. Red meat gets a bad rap, some of which is deserved since the heavily marbled meats are more tender and often have more flavor. But lean red meat is a tremendous source of important nutrients such as iron and phosphorous.
  • Pork, the so-called “other white meat,” also gets a bad rap, but if you ask for a lean cut with little marbling, you’ll have a tasty and nutritious protein.

Complete Proteins Vs Incomplete Proteins

When choosing a protein, consider quality. Proteins can be divided into two categories: complete and incomplete.

  • Complete proteins contain the appropriate amounts of all essential amino acids (amino acids the body cannot produce). Included in this category are animal/soy proteins.
  • Incomplete proteins lack the appropriate amount of one or more essential amino acids. Included in this category are plant proteins (excluding soy).

Generally speaking, complete proteins are of better quality than incomplete proteins. But you can also create complementary proteins to form a complete protein to ensure that your body gets all the amino acids it needs. Examples:

  • Grains and legumes (rice and beans)
  • Grains and dairy (oatmeal and milk)
  • Nuts/seeds and legumes (hummus, chickpeas and sesame seeds)

 How Much Protein?

Healthy, active individuals should aim to consume 0.6 to 0.8 grams of protein per pound of bodyweight. If a person weighs, say, 180 pounds, then the protein target would be between 108 to 144 grams of protein per day. Generally speaking, the leaner and more active you are, the higher the protein intake should be on that scale. That might sound like a lot, but consider how much protein is in common foods such as the ones listed below:

  • Chicken (4 ounces, skinless, size of a deck of cards): 35 grams
  • Tuna (6 ounces, packed in water): 40 grams
  • Fish (6 ounces of cod or salmon): 40 grams
  • Lean red meat (4 ounces): 35 grams
  • Lean pork (4 ounces): 35 grams
  • Reduced-fat tofu: 30 grams
  • Cottage cheese (1 cup, 1% or 2% fat): 28 grams
  • Milk (1 cup of 1%, 2%, or fat-free): 8 grams
  • Pre- or post-workout recovery meal: 20 to 45 grams

In general, protein intake that greatly exceeds the recommended level does not help build extra muscle mass.


  • Verstegen, Mark, and Pete Williams. Core Performance: The Revolutionary Workout Program to Transform Your Body and Your Life. Pennsylvania: Rodale Press, 2004.
  • Verstegen, Mark, and Pete Williams. Core Performance Essentials: The Revolutionary Nutrition and Exercise Plan Adapted for Everyday Use. Pennsylvania: Rodale Press, 2006.
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