The Nutrition Series: Protein 101

Protein: The Muscle Maestro

Protein is a fine white powder that comes in plastic tubs and is generally consumed with water—insert grinning troll face here. Jokes aside, protein and ultimately, amino acids, form the building blocks of life. When humans consume protein as food, the body breaks it down into amino acids through metabolic processes. Those amino acids are utilized for the formation of new proteins that serve numerous functions in the body. These can include growing and maintaining tissues, biochemical reactions, signaling as hormones, pH balance, structure, fluid balance, immune health, nutrient transport and storage and even energy during periods of extending fasting. While there are over 500 amino acids that have been revealed in nature, there are only 20 that are common across all life forms, nine of which are essential and must be consumed through our diet.

Breaking Down Amino Acids

Before beginning a discussion on amino acids, its important to understand the terms essential, non-essential and conditionally essential amino acids. While much of the meaning can be derived from the name alone, a more detailed presentation is as follows:

Essential Amino Acids

All 20 of the amino acids are essential for proper growth and function however, as I mentioned, nine of them must be consumed through diet alone. Those include histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.

I’d like to highlight leucine as particularly important. Current existing research and literature on leucine indicate that it’s an essential component for stimulating muscular hypertrophy as well as preventing muscle loss. If you remember any of the essential amino acids at all, leucine would be it!

Conditionally Essential Amino Acids

Several amino acids can be produced within the body, including those that are classified as “conditionally essential”. These are called conditional because the body has difficulty producing them under certain circumstances such as illness, injury, pregnancy or various types of traumas.

For example, under normal homeostatic conditions, the body readily produces glutamine from glutamate but under conditions such as injury, illness or stress, the body may have difficulty in meeting glutamine demands and therefore, supplementation is beneficial.

Conditionally essential amino acids include arginine, cysteine, tyrosine, proline, glutamine, glycine and serine.

Non-Essential Amino Acids

Non-essential amino acids can be produced by the body under all conditions and are therefore, non-essential in your diet. These include alanine, asparagine, aspartic acid, and glutamic acid.

Sources of Protein

There are a plethora of options when it comes to choosing a source of protein. Fundamentally, sources of protein fit into two categories: whole food sources and supplementation. We’ll focus on whole food sources first. Supplementation, while important for some, should be considered when an individual isn’t getting enough protein through their diet in order to meet their needs. This isn’t necessarily only applicable to active individuals (who by default require more protein); think seniors, vegetarians, vegans, individuals on restrictive diets etc. Protein supplementation is a tool. Let’s dive in!

Whole Food Sources of Protein

Whole food sources of protein include a variety of options including but not limited to meat, dairy, nuts, select vegetables, select grains and beans. These sources are not only excellent for obtaining required your required daily protein for proper bodily functioning, but they are also rich in nutrients, minerals and vitamins essential for optimal health. Here are some high-quality food choices for the categories listed above:

Meat	Dairy	Nuts	Vegetables	Grains	Beans
Chicken	Milk	Almonds	Watercress	Brown rice	Kidney beans
Beef	Cheese	Hazelnuts	Spinach	Oatmeal	Pinto beans
Turkey	Yogurt (Greek)	Walnuts	Broccoli	Quinoa	White beans
Pork	Goat cheese	Peanuts	Alfalfa sprouts	Cornmeal	Black beans
Salmon	Cottage cheese	Chia seeds	Chinese cabbage	Kamut	Lima beans
Tuna		Pumpkin seeds	Asparagus	Teff	Fava beans
Mackerel		Sunflower seeds	Mustard greens	Whole-wheat pasta	Soybeans
Anchovies		Peanut butter	Collard greens	Wild rice	Chickpeas
Trout			Brussel sprouts	Millet	Back-eyed peas
Eggs*			Cauliflower	Couscous	Pigeon peas
				Buckwheat	Split peas
				Farro	Lentils
					Edamame

*Not considered meat or dairy but generally lumped in with poultry

It should be highlighted that there are special considerations when choosing protein sources. Not all protein sources are created equal, which is why there is an emphasis on choosing a variety of sources when it comes to building your diet.

Amino Acid Content

What types of aspects can vary, you ask? Let me enlighten you! You haven’t forgotten about amino acids yet, have you? Good! One major aspect that can vary between protein sources is the amino acid content. Meat and dairy sources, for example, have all 20 required amino acids in sufficient quantities. Vegetables, on the other hand, may or may not contain all 20 amino acids and potentially not in sufficient quantities. That is why it is vitally important for vegetarians and vegans to consume a wide-variety of non-animal based proteins in order to satisfy their protein requirements.

Protein Content

As you might expect, protein sources can also vary in the content of protein they contain. This becomes important when you are attempting to stay within a specific caloric intake range while also meeting a demanding protein requirement. If one was, for example, attempting to lose weight while also maximizing protein intake to maintain or even build muscle under certain conditions, it would be prudent to choose a source that was high in protein to get the best bang for your buck.

To highlight this, let’s look at a 6oz cooked chicken breast. This contains ~40g of protein and ~185 calories. If one were to attempt to get this amount of protein from let’s say, walnuts, you’d have to consume more than 9oz totaling in at ~1,700 calories. Not ideal.

Fat Content

Lastly, it’s important to consider the fat content within the sources of protein you are consuming. I’d like to highlight that this is not necessarily a "less animal fat is better" argument, there is certainly literature highlighting the importance of animal fats within our diets and I for one am an advocate. Fat content is simply one concept of many to be familiar with.

When selecting your protein sources and ultimately planning your macronutrients, it is essential to consider fat content. Let’s revisit our chicken and walnut example, shall we. Our 6oz cooked chicken breast contains ~2g of fat while the equivalent in walnuts required to hit the same amount of protein also contains a whopping a ~168g of fat! A less hyperbolic comparison would be 6oz of cooked lean ground beef which contains ~31g of fat. It’s a seemingly subtle, yet crucial difference to understand. Over the course of a day or more vitally, a week, this amount of fat can add up to a substantial excess and could potentially torpedo your weight loss strategy and journey.

Protein Supplementation

Interestingly, protein supplementation is often the first consideration for those new to exercise when it should ultimately be your last. This is why it’s called “supplementation” and not “foundation”. Consuming a well-rounded diet with adequate protein for your activity level is a good place to start for those who are new to exercise. Eventually, however, you may need to investigate supplementing your diet with additional protein. While there are endless brands of protein on the market, there are really only a handful of types:

·        Whey concentrate;

·        Whey isolate;

·        Casein protein;

·        Soy protein;

·        Egg white protein;

·        Pea protein; and

·        Hemp protein.

Lets break the main three out in more detail.

Whey Concentrate

Whey concentrate is found in milk and is the most commercially available protein supplement on the market and the fastest to enter the bloodstream following consumption. It has an excellent, full amino acid profile with ample leucine content and is generally cheap with a wide variety of flavors. The drawback to whey concentrate is slightly more fat and lactose content when compared with whey isolate however, this shouldn’t be a massive consideration unless you have specific dietary restrictions (i.e., a bodybuilder in prep).

Whey Isolate

Whey isolate has all of the benefits of whey concentrate (fast acting, full amino acid profile, high leucine content) with less carbs and fat. Again, this is only important if you have specific dietary restrictions. Whey isolate tends to be more expensive as well, so if you don’t need it, you are better off buying whey concentrate.

Casein Protein

Casein protein (also found in milk) has an interesting property that makes it particularly useful for certain individuals and circumstances. The acidic environment of the stomach causes casein protein to clot and form a gel which takes almost twice as long to digest when compared to whey concentrate. Why is this valuable? Individuals may choose to consume this type of protein when they want their bodies to remain fed with protein for longer durations, such as during sleep when your body is most actively making new muscle. Casein protein is a great option for athletes and if you know you are about to undergo extended periods of fasting (i.e., sleep, long trips, hikes etc.).

There is some evidence to suggest that simply adding a small amount of extra virgin olive oil to your whey concentrate shake may result in slowed digestion, which is likely sufficient for most individuals if you are on a tight budget.

Protein Requirements

With all the above in mind, the most obvious question then is, how much protein do I need? Good question! And, for a lot of individuals, its not as much as you think. The following represents current accepted recommendations for protein intake for varying levels of activity:

Sedentary Individuals: 0.36 grams/lb (0.8 grams/kg) - Minimal physical activity.

Lightly Active Individuals: 0.36 - 0.5 grams/lb (0.8 - 1.1 grams/kg) - Engage in light exercise or activity 1-3 days per week.

Moderately Active Individuals: 0.5 - 0.7 grams/lb (1.1 - 1.5 grams/kg) - Engage in moderate exercise or activity 3-5 days per week.

Endurance Athletes: 0.6 - 0.9 grams/lb (1.3 - 2.0 grams/kg) - Engage in regular endurance training (e.g., long-distance running, cycling).

Strength Training Individuals (Light to Moderate): 0.7 - 0.8 grams/lb (1.5 - 1.8 grams/kg) -Engage in resistance training with light to moderate intensity.

Strength Training Individuals (Heavy): 0.8 - 1.0 grams/lb (1.8 - 2.2 grams/kg) - Engage in intense resistance training with heavy weights.

Very Intensely Active Individuals: 0.9 - 1.1 grams/lb (2.0 - 2.4 grams/kg) - Engage in high-intensity training or multiple daily workouts.

Protein is but one important component of a complete and full diet. The importance of obtaining adequate protein through your diet cannot be stressed enough. As has been shown, protein is not only required for essential homeostatic bodily functions, but is also crucial for repairing, growing and maintaining muscle tissue (which if you're reading this you're likely particularly interested in). Whether meeting your protein requirements through whole food sources along or mixed with supplementation, ensure you are paying close attention to hitting the minimum recommended guidelines.