The Protein Question

Do I really need it? Why? How much? What kind

By now, hopefully you know how important it is to consume adequate amounts protein. You have probably been told, read or heard somewhere, how important it is in building muscle. This is indeed true but protein is much more important than just helping you get bigger muscles. It is essential in the proper functioning of your body (major structural component of our muscles, nervous system, brain, blood, skin and hair and is used by the body as a transport mechanism for vitamins, minerals, oxygen and fats).

Protein basics

All proteins are made up of amino acids. There are 20 amino acids that are needed for human growth and metabolism. Most of these amino acids can be produced by the body but nine of them, called essential amino acids must be obtained by food. Our bodies can’t produce these and that’s why it’s essential to include them in a balanced diet. These essential amino acids are: Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, Valine.

Complete proteins are proteins (animal sources such as milk, egg, poultry, fish, meat, soy) that contain all 9 essential amino acids. Although animal source proteins provide all essential amino acids, there is a concern about the typically high amount of saturated fat that these foods have when compared to plant-based foods.

Incomplete proteins are protein sources (plant foods) that do not contain all essential amino acids. This is especially important to consider for vegetarians and vegans as they need to pay special attention to eat a variety of plant foods to make sure they consume enough of all amino acids. That said, with the proper combination, vegetable proteins can provide the same benefits as animal proteins.

Protein types

Topping the list of high quality proteins are meat, egg, poultry, fish, and soy. Milk, and all of its components (whey, casein) is closely behind.

Whey protein can be divided into whey powder (11%-15% protein), whey concentrate (25%-89% protein) and whey isolate (>90% protein). Whey isolate is lactose free. This type of protein is quickly absorped and digested and ideal for muscle regeneration after a workout. It has a much larger ability for muscle protein synthesis stimulation that casein or soy proteins.

Casein is released into the bloodstream much slower then whey and can provide a more constant supply of amino acids. A combination of whey and casein seems to have the greatest muscular strenght improvements.

Plant-based protein sources

Soy is the only vegetable protein that contains all nine essential amino acids and a high concentration of branched-chained amino acids. Just like whey protein, soy can be divided into three types (soy flour, concentrate, and isolate) depending on the protein content. This type of protein has been in the news for its health benefits. However, specific soy components (isoflavones) are phytoestrogens which are a form of estrogen, which could have “drug-like effects in the body” (FDA, 2000). There is still a lot of research to be done but it can be said that soy protein can have valuable health benefits. FDA determined that diets with four daily soy servings can reduce levels of LDL by as much as 10 percent (1% drop in total cholesterol can equal a 2 percent drop in heart disease risk). For more information about soy, read my blog “The Soy Controversy.”

Textured Vegetable Protein is made from soy flour and is often used as a meat alternative in vegetarian hot dogs, etc.

Some high-protein plant-based food sources are: lentils (9g), black/pinto/red beans (8g) tempeh (16g), soy milk (8g), tofu (10g), quinoa (4g), pumpkin seeds (9g), peanuts (7g).

So what does that all mean?

  • The most important aspect of protein consumption is to ensure consumption of the nine essential amino acids. This can be accomplished through complete proteins or combination of incomplete proteins.
  • Essential amino acids do not have to be consumed in one food or even one meal. You can consume them over the course of the day to ensure you are including all nine essential amino acids in your diet.
  • When choosing a protein powder, pay attention to the type of protein (isolate is better than powder or concentrate).

Daily protein intake recommendations:

There is much discussion about how much protein is the right amount and in the end you have to know what’s right for you. But to help you make an informed decision, below are some recommendations that are based on physical activity level and on how much protein a person needs per day to promote physical strength, muscle growth, and overall health:

  • Minimal physical activity:  0.4 – 0.5 grams per pound of body weight
  • Moderate physical activity: 0.5-0.6 grams per pound of body weight
  • Intense physical activity:  0.7-0.9 grams per pound of body weight

Word of caution: Even though excessive protein consumption has not been shown to have negative health effects in healthy/active people, individuals with kidney disease, diabetes, liver disease, or osteoporosis can be at risk. “Chronic high protein intake (>2 g per kg BW per day for adults) may result in digestive, renal, and vascular abnormalities and should be avoided.” (Wu, 2016)

Stay happy and healthy

-Dr. Maria

Sources:

Hoffman, J. R., & Falvo, M. J. (2004). Protein – Which is Best? Journal of Sports Science & Medicine, 3(3), 118–130.

Cribb, P. J., Williams, A. D., Stathis, C. G., Carey, M. F., & Hayes, A. (2007). Effects of whey isolate, creatine, and resistance training on muscle hypertrophy. Medicine and Science in Sports and Exercise, 39(2), 298-307.

Wu, G. (2016). Dietary protein intake and human health. Food & Function 7(3), 1251-65.

Dietitians of Canada, American College of Sports Medicine, & American Dietetic Association. (2000). Joint position statement: Nutrition and athletic performance. american college of sports medicine, american dietetic association, and dietitians of canada. Medicine and Science in Sports and Exercise, 32(12), 2130.

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