Industry-Presented Blog: A Tale of Two Proteins: Plant vs Animal for Fitness

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Industry-Presented Blog: A Tale of Two Proteins: Plant vs Animal for Fitness

Chris Mohr |  Oct. 12, 2017
Viewpoints presented in this blog post reflect opinions of the author and do not necessarily reflect positions or policies of ACSM.

A recap and Q&A of the webinar presented by the Egg Nutrition Center on September 20, 2017.

When you think of protein, you might think of powder mixed with water in a shaker bottle. Or maybe it's eggs, chicken or steak. All can have their place "on the table," but they're certainly not the only options.

Protein comes from many different sources and also does more for the body than just repair muscle. Protein is made up of amino acids and is required for nearly everything that your body does to function properly. Amino acids are referred to as the building blocks of protein - imagine the structure of a brick wall. One brick by itself only has so much strength, but many stacked on top of one another can create an entire wall, build houses or even buildings. The same goes for amino acids - individually, they're not as "effective" - but when strung together to form an entire protein, they can ultimately help build and repair muscle along with assisting with their many other "jobs" in the body.

Amino acids are classified into two categories - essential and nonessential.

Essential amino acids, which make up almost half of the 20 amino acids, refer to those that must be ingested since our body doesn't produce them. Without eating these nine essential amino acids, our bodies are not able to function properly.

Dietary protein refers to the foods we eat that have at least some of the essential amino acids. Not all dietary protein is the same. Though all protein contains 4 calories per gram, just like carbohydrates, there are three different classifications based on the essential amino acid profile - complete, incomplete and complementary.

Protein Type Definition Examples
Complete Protein A food source that provides all nine essential amino acids necessary for dietary needs. Meat, Poultry, Fish, Milk, Eggs
Incomplete Protein A food source that lacks one or more of the nine essential amino acids. Nuts, seeds, whole grains, vegetables, legumes (beans)
Complementary Protein Two or more incomplete proteins paired together to provide all essential amino acids creating a complete protein. Beans and rice
Peas and corn
Almonds and peanuts
Nut butter and whole grain toast

NOTE: Incomplete proteins, like those mentioned above, aren't "bad" or useless, they just don't provide all essential amino acids when eaten independently.

Complete proteins are primarily found in animal sources such as meat, poultry, fish, dairy, pork and eggs. There are exceptions, like soy. When you eat these foods, you're getting all of the essential amino acids the body needs to carry out the many jobs amino acids have in the body such as regulating body processes, enzymes and hormone function and building muscle tissue, to name a few.

Incomplete protein are plant based proteins, which are usually limited in one or another amino acids. Beans, for example, are low in methionine. When combined with rice, which has more methionine but is instead lower in lysine, they complement one another and make a complete protein.

The logical question, then is:

Can vegetarians eat enough protein?

Let's first go over the different types of vegetarian diets you might see.

Types of Vegetarian Diets: What is it?
Semi-Vegetarian (Flexitarian) A plant-based diet where meat is occasionally consumed.
Lacto-ovo Vegetarian A plant-based diet that allows dairy and eggs but excludes red meat, fish and fowl.
Lacto-Vegetarian A plant-based diet that allows milk, cheese and yogurt but excludes eggs, red meat, fish and fowl.
Vegan This is a plant-based diet that excludes all animal products (including honey in some cases).

It is possible for individuals to consume enough protein when eating a plant-based diet of any kind, including a vegan diet. The challenge is that plant-based foods have less protein than animal-based foods and they are higher in fiber so it can be more challenging to get the appropriate quantities. For example, 1 ½ cups of beans would give you the same amount of protein (21 grams) as a palmful (3oz) chicken breast or fish.

To ensure vegetarian athletes are consuming enough of the right types of proteins, combine foods to create complete proteins. Ideally this will be done at each meal. To highlight how nutrition research changes, it was first thought that complementary proteins had to be eaten at the same meal (e.g., beans and rice). The school of thought then changed to suggest that these proteins could be eaten within a 24-hour period (e.g., beans for breakfast, rice at dinner). Now that it's understood that we do not store protein, or subsequently amino acids, researchers are starting to think it would be best if they could be eaten at the same meal to maximize the benefit.

Fortunately, we have access to a variety of protein sources and are not just limited to one or another. Variety is key when it comes to protein, as this balance provides the nutrition we need to thrive and benefit from the protein we consume.

To watch the complete webinar, visit:

If you are a registered dietitian and would like to receive one continuing education credit for watching the full webinar, visit:

Below are answers to questions asked during the webinar:

Q: You mentioned how we get complete proteins. Why is a complete protein better for the body as opposed to an incomplete protein?

A: Complete proteins offer all of the essential amino acids. Incomplete proteins do not, so they need to be combined with other proteins to get all of the essential amino acids (EAAs) (beans and rice, for example). Beans are low in methionine, while rice is low in lysine. Put them together and you have the EAAs that you need.

Q. How does cooking eggs, versus drinking egg whites raw, effect the ability of the body to absorb the nutrients (protein)?

A. Cooking eggs improves protein digestion. The availability of egg protein is 91% with cooked egg and only 50% with raw egg. That means if you eat a whole egg raw, you're only getting about 3 grams into your system versus eating a whole cooked egg which would provide almost 6 grams of protein.

Q: Can you elaborate on the statement "we don't need that much protein?" It is easier to fill up on protein and feel full on fewer overall calories than it is on carbs. So would you not want someone having a relatively high (~30%) protein intake? If the excess gets excreted, wouldn't it be a better option than having too many carbs, which turn into fat?

A: Research suggests people should aim for about 25% to 30% of their total calorie intake from protein. Protein is filling and is necessary to build and maintain muscle. And this total intake should be balanced with quality carbs and quality fat.

Q. Can you elaborate on the difference in egg white and egg yolk, for example how choline negatively effects for prostate cancer and growth ( and Ornish Study)?

A. All of the choline is found in the egg yolk. While I am not familiar with the research you reference, neither the International Agency for Research on Cancer nor the American Cancer Society mention choline in their cancer prevention or treatment recommendations. In fact, most of the research has demonstrated many positive associations between choline intake and health outcomes such as the nutrient's impact on fetal brain development and brain health later in life as well.

Q: What is your opinion of ultra-filtered skim milk (i.e., Fairlife) with increased protein and decreased lactose?

A: I think they're a great way to boost protein, particularly around meals that may otherwise not have too much (like cereal, for example). And, if a person is lactose intolerant, this offers them a nice option to get the nutrition from milk without the lactose.

For more information on protein intake: