Before You Continue, Part 1 Of This Series Is Recommended If You Haven’t Read It. —> CLICK HERE

Welcome to Part 2 of my sports nutrition blog series.  In Part 1 we discussed the base understanding of calories and metabolism.  If you haven’t read part 1, I would highly recommend it before continuing on.  Before you understand macronutrients, you must first understand calories and some basics on human metabolism.  Without that information you run the risk of missing the big picture.  So again, here is part 1 if you haven’t read it.


In the next 3 blogs within this series, I will be discussing the 3 primary macronutrients.  A macronutrient is an energy yielding nutrient, or a type of nutrient that provides us with direct energy.  In Part 1 you learned that a calorie is in fact direct energy, a macronutrient is simply a unit of that energy.   Overall calories can be broken up into 3 main parts, Carbohydrates, Protein, and Fat.   Alcohol can also be classified as a macronutrient, but it doesn’t provide us with much benefit when discussing health and wellness, so we generally leave it out.  It is important that we dive into carbohydrates, protein, and fats so that we can get a grasp on their roles within our metabolism.  Each of these macros play a unique metabolic role and can affect the overall outcome of your goals.

Atwater System

In the early 19th century Dr. Wilbur Olin Atwater set in motion what is now known as the “Atwater System”.  The Atwater system is a method for getting a close guesstimate of  the energy in food.  There has been much controversy around this topic, particularly when looking at the nitrogen component of protein, but to this day there is no other proposed system.  To keep things simple, the atwater system approximates the amount of calories in carbohydrates, protein, and fats.  It attempts to get an idea of the usable energy within these 3 macros considering human metabolism.   If you remember from PART 1 of this series, we discussed the importance of the 2nd law of thermodynamics.   This takes into count energy lost during metabolism such as heat.

Protein – 4 calories per gram

Carbohydrate – 4 calories per gram

Fat – 9 calories per gram

The atwater system takes into count a few things and attempts to give us a guesstimate of “Metabolizable Energy”.   The gross energy in food of course is a main component, and then energy lost in feces, urine, secretions and gases must be accounted for.  In this section I don’t want to branch off too far into the atwater system, but I will be sure to make a post in the future that is dedicated to a better understanding of it.

Wrapping Up Macronutrients

As we know from the previous blog post, calories aka energy, is an important component when setting up your diet.   The total of the calories can be split into the 3 main macronutrient groups carbohydrates, protein, and fats.  In the next 3 blog posts (this one included) I’m going to do my best to give you some detail on each of these energy sources.


The first macronutrient I will be diving into is protein.  I personally find protein to be the single most important energy source in your diet.  This is especially true for athletes, or those working out regularly.   Now this isn’t discrediting the other macros, they all play a crucial role in metabolic processes.  Weight gain, weight loss, performance, etc… each of the macros have an important role.

What Is Protein?

Well technically speaking proteins are any nitrogen based organic compounds that consist of large molecules composed of one or more chains of amino acids and are an essential part of all living organisms, especially as components of body tissues such as muscle, hair, collagen, etc.  Of course today, we are discussing protein from foods and their importance in our dietary guidelines.   It is, however important to recognize, protein is in fact something all living organisms poses in several forms and is essential for life.  Our skeletal muscle tissue (a form of complete protein) for instance is synthesized from other protein sources we consume.    As bizarre as it may seem, other living organisms have complete and incomplete protein sources, so to support our protein needs we consume these living organisms.

Amino Acids

The word protein refers to a molecule composed of amino acid chains.  In nature, there are over 100 different amino acids, the human body however, only utilizes 20 total amino acids, because we require these 20, we refer to them as biologically active.  Of course other amino acids outside of these 20 are not used by the human body, therefor we refer them as “non biologically active”.

The human, being a biological machine, can create or synthesize 11 of the 20 required amino acids.  This of course would render them “non essential” in our diets.  We refer to these as the “non essential amino acids”.   On the flip side, that would mean we must obtain the other 9 amino acids in our diet.  This of course would make them “essential” for us to obtain, which earns them the name “essential amino acids”.

Non Essential Amino Acids

  • Alanine (considered conditionally essential)
  • Arginine
  • Asparagine
  • Aspartic Acid
  • Cysteine
  • Glutamic Acid
  • Glutamine
  • Glycine
  • Proline
  • Serine
  • Tyrosine

Essential Amino Acids

  • Arginine (considered conditionally essential)
  • Isoleucine
  • Histidine
  • Leucine
  • Methionine
  • Lysine
  • Phenylalanine
  • Tryptophan
  • Threonine
  • Valine

As you may have noticed above, the amino acid Arginine is listed in both categories.  This is because Arginine is considered to be “conditionally essential”.   The conditional aspect means, that whether or not it is essential is based off the individuals health status.  Though we do synthesize this amino acid, it is not produced in adequate amounts, therefor we must consume it in our diets.   Those with certain health problems may however be advised to increase their Arginine intake.

Some Dietary Sources Of Arginine

  • Animal sources include:
    • Cottage Cheese
    • Ricotta
    • Milk
    • Yogurt
    • Whey Protein
    • Beef
    • Pork
    • Chicken
    • Lobster
    • Salmon
    • Shrimp
    • Tuna
  • Plant sources include:
    • Wheat germ
    • buckwheat
    • granola
    • oatmeal
    • peanuts
    • coconut
    • pecans
    • almonds
    • sunflower seeds
    • soybeans

Complete and Incomplete Proteins

We classify dietary protein sources based off of their amino acid profile.  A complete protein would contain all of the essential amino acids (listed above) in sufficient amounts.  Incomplete protein sources on the other hand, would be ones that either do not have all 9 of the essential amino acids or do not contain sufficient amounts of them.  Generally speaking, complete proteins are going to be found in animal based foods while many incomplete proteins are found within plant based foods.   With that being said, there are plant based foods that are considered to be complete sources or protein.   Many times however, those consuming a plant only based diet, must vary their food choices and in many cases, use supplemental protein to assure a complete essential amino acid intake.

  • Complete Protein Sources
    • Chicken
    • Beef
    • Milk
    • Yogurt
    • Whey
    • Fish
    • Quinoa
    • Chi Seed
    • Buckwheat
  • incomplete Protein Sources
    • Many nuts and seeds
    • Grains
    • Legumes
    • Many Vegetables

Determining The Quality Of Protein

Now we know that protein is essential in our diets, we also know the difference in complete and incomplete proteins.  But what about the quality of each protein source?  Is there a difference in protein quality from different sources?  More than likely you have heard someone at some point try and say that a certain protein source is better than another.  Many times it’s the sales rep at the front desk of your local supplement store.  “Whey Isolate is superior and all other protein is crap!”  This seems like something I’ve heard a time or two.  So is there a difference in quality?

Each amino acid peptide sequences effects the quality of the protein it makes up.  For instance there are certain ideal amino acid ratios that allow us as humans to utilize dietary protein to its max. Basically we can use these ratios to rate our protein sources.  Also each Amino Acid has specific roles to undergo, some professionals have found reason to believe that certain amino acids such as Leucine, Isoleucine, and Valine (Branch Chained Amino Acids) are more important for Protein synthesis.  So keeping it simple, Professionals have found that there is a specific ratio of Amino Acids that is “ideal”


The PDCAAS is an acronym for Protein Digestibility Corrected Amino Acid Score. This is simply a chart that allows us to rate the quality of a protein based off human amino acid requirements and our ability to digest them (bioavalibility).  This method was adopted by The Food and Drug Administration (FDA) in 1993.  It is now considered the “best” method for evaluating protein quality.  There are other methods such as the Protein Efficiency Ratio (PER) and the Biological Value (BV). The FDA however has gone far enough to suggest that other methods of evaluating protein are inferior

Utilizing the PDCAAS methodology, the quality of the protein rankings are determined by comparing the amino acid profile of the specific dietary protein against a standard amino acid profile with the highest possible score being a 1.0. This score means, after digestion of the protein, it provides per unit of protein 100 percent or more of the indispensable amino acids required.  So basically 1.0 is a perfect 100% score, and we go down from there.  Below is a break down of different dietary sources of protein and their PDCAAS score.

1.00 casein (milk protein)
1.00 egg white
1.00 soy protein
1.00 whey (milk protein)
0.99 mycoprotein
0.92 beef
0.91 soybeans
0.78 chickpeas
0.76 fruits
0.75 black beans[disambiguation needed]
0.73 vegetables
0.70 Other legumes
0.59 cereals and derivatives
0.52 peanuts
0.42 whole wheat

Quick Note About Protein Quality

I would like to mention that the concept of protein quality in translation to results in the gym may be overblown at some point.  As we can see above, there is relevance to the bioavalablity of different protein sources.  With that being said, this has been exaggerated to be used as a tool to scare people into buying “the most superior” products.  Though I do encourage good quality protein sources in your diet, it should be noted that the bigger picture may be focusing on getting in enough protein daily to support your overall goals.

How Much Protein Do You Need?

When it boils down to it, quality isn’t the entire picture.  Now please don’t mistake me, quality does have role in this, and I do not mean to down play that, but I can tell you from personal experience, and from referencing some solid scientific research, the amount of protein consumed plays a large role.   There are many cases that I will have someone looking to myself or fellow trainers for results and the first question we ask is “what does your diet look like”.   The response in many cases is “well I eat clean” or “I eat a high protein diet”.   This group of people generally is not aware of the amount of macronutrients they consume, protein included.   They simply focus on the “quality” of their diets and not the overall intake.  In most cases when they start to hit their numbers on a daily bases, results follow quickly.

Above all, hitting your total calories and your macro nutrient goals, like protein, are at the top of the priority list. So before you get super hype about only eating high quality foods, you should first start by setting total daily protein intake goals… regardless of the source. You of course can then refine this to choosing mostly high quality proteins.

So How Much Do You Need?

“You need 1-2 grams of protein per pound of body weight” or so we have all heard.   That seems to be the traditional response when it comes to asking a personal trainer or fellow weight lifter on the gym floor.  Now the good news is, it’s not terrible advise.  On the other hand, it is a very generalized statement and does not fit all scenarios.   I would like us to take a deeper look at protein requirements and see how we may be able to get a more specific answer.

The old school methodology of protein consumption was to simply eat about 1 – 2 grams of protein per pound of body weight.  As a matter of fact, this concept has been so deeply ingrained in the gym community that not many people question its validity.  Of course that’s not what this blog is about though, we are here to take a deeper look and level of understanding.   Below are a few scientific studies on the topic.

  • Walberg et al. (1988) found that 0.73g/lb was sufficient to maintain positive nitrogen balance in weightlifters that were dieting (in a negative energy balance) over a 7 day time period.
  • Tarnopolsky et al. (1988) found that only 0.37g/lb was required to maintain positive nitrogen balance in elite bodybuilders over a 10 day period. 0.45g/lb was sufficient to maintain lean body mass in bodybuilders over a 2 week period. The authors suggested that 0.55g/lb was sufficient for bodybuilders.
  • Lemon et al. (1992) found no differences in muscle mass or strength gains in novice bodybuilders consuming either 0.61g/lb or 1.19g/lb over a 4 week period. Based on nitrogen balance data, the authors recommended 0.75g/lb.
  • Hoffman et al. (2006) found no differences in body composition, strength or resting hormonal concentrations in strength athletes consuming either 0.77g/lb or >0.91g/lb over a 3 month period.

Based off of the above research the 1g of protein per pound of bodyweight would be considered an exaggeration.  For those suggesting 2g of protein per pound, this would be a very high estimate, nearly 2.5 times the suggested amounts above.  Based off of most research and review studies, 0.82g/lb of protein would be the highest limit recommended (Phillips & Van Loon, 2011), and many studies, as you can see above, conclude lower than this. 0.82g/lb at this point seems to be the higher end of the spectrum and this recommendation often includes a double 95% confidence level, meaning they took the highest mean intake at which benefits were still observed and then added two standard deviations to that level to make absolutely sure all possible benefits from additional protein intake are utilized.

At this point the average suggested 1g -2g of protein per pound of overall bodyweight is a reach, especially on the 2g per pound side.  Several of the above studies also looked at athletes that in some cases trained intensely for 1-1.5 hours per day with heavy resistance training.   Also some of the studies looked at athletes in an energy restricted state aka a negative energy balance.  Even with these variables, it seems that the 1g – 2g per pound model is an over exaggeration.

Could You Need More Protein Than The Above Suggested? 

There has been some recent research to suggest that some scenarios may need more protein than the above studies suggest.  Now these reviews have been challenged and at this point it is still not fully clear if the 0.82g threshold is sufficient or if some scenarios may warrant more protein.   The most popular referenced research suggesting more protein would be Eric Helms look at protein requirements.  In this article he shows research and presents and argument in favor of higher protein in very lean athletes that are undergoing a large energy restriction.   Basically lean athletes that are dieting very hard, he would suggest, require more protein.    There is some great information here and should potentially be taken into count when recommending protein intake.   Below is a link to the Eric Helms paper for more clarity.

 “A Systematic Review Of Dietary Protein Intake During Caloric Restriction In Lean Athletes:  A Case For Higher Protein”

What Do You Recommend For Your Clients?

It first depends on the situation.  Each person I think has a different requirement, for several reasons.  The amount of exercise they do daily / weekly, the intensity and type of training they perform, their current body fat %, and even their genetics can play a role.  In addition a persons personal preference for macros can affect how much I would recommend.

I generally work with athletes, or at least that is the majority of my clients these days.   Many of these clients are bodybuilders, or extreme body transformations.  These are clients that are in calorie restricted states for extended periods of time and that do resistance training at intense levels, 5-7 days weekly.   For these clients, I personally like to use the Eric Helms recomendations above.   2.3g – 3.1g of protein per Kg of Fat Free Mass is my go to.  Again this is referenced in the above linked review paper.

Step 1:  Take your clients total weight

Step 2: Multiply by body fat % to find Fat Mass

Step 3: Subtract Fat Mass From Total Weight, leaving you with Fat Free Mass

Step 4: Divide Fat Free Mass by 2.2 to get it in Kg

Step 5: Multiply Kg of Fat Free Mass by the recommended protein grams (2.3 – 3.1)

This is a very easy way to get a target number, and I like that fat free mass is taken into account.  In many formulas we look at overall weight but do not consider the amount of lean tissue a person has.   It is an obvious observation that the more skeletal muscle someone may have, the higher the protein requirement may be.   This makes taking total weight into account not as accurate.   With that being said, it does not completely discredit other methods.   More than likely if you are getting the 0.82g per pound of total body weight estimate, you will be ok.  I have however found great results with the Eric Helms recomendations listed above.

How Much Protein Should I Consume Per Meal?

Another very common fallacy in the weight lifting community.   “You can only use 25g of protein per meal” or  “50g per meal” or basically some number within that realm. The concept developed here was based off of the assumption that your body can only absorb so much protein per sitting.  This fuels the whole “eat every 2 hours debate” as well.  In a perfect world, spreading out nutrients over a more extended period may have some benefits.   With that being said, this idea has been blown out of proportion.

The Truth

Let’s take this opportunity to put that old myth to rest, Assuming that you have a healthy digestive system, the amount of amino acids you absorb in a sitting, regardless of the meal size is very great! Absorption is simply referring to how much of the nutrient was utilized for something during the digestive process. Think of it this way, if you didn’t absorb most of the nutrients in the food, you would most likely be sick to your stomach and in the bathroom for long periods of time post eating.

Even from an evolutionary standpoint it doesn’t hold up. Throughout the history of the human species it was unlikely that we were able to have 8 evenly spread out meals per day. We wouldn’t survive without an efficient digestive system that allows us to consume large amounts of nutrients in one sitting. Now what these folks are most likely getting at, is how much of the amino acids are actually getting to the muscle tissue for rebuilding. So how much of them are we actually utilizing for muscle growth. When we consume protein and its broken down via the digestive system into its prospective amino acid ratios. The amino acids are dived up to help with several processes such as kidneys, heart, skin, etc…. So the question is not neccessarly how much of the protein do we absorb, rather its how much of it goes to helping us build bigger muscles!

Don’t Stress, Just Hit Your Numbers

At the end of the day your total amount of protein consumed daily is where it’s at.   Sure, we can get into saying that timing, quality, and how much per meal, can play a role.  But this is far from the big picture.   The big picture is that you need a certain requirement of protein daily to sustain your goals and fuel your personal goals.   By getting in the habit of hitting these numbers daily, you can then refine it to better quality, more spread out meals, etc…    But even if you eat only 2 meals daily, but you’re hitting your protein requirment, you will more than likely see great results.


I hope you enjoyed the protein section of my blog.  Again, I know this is a lot of information to take in, but it should give you the edge when looking at dietary recomendations with yourself and your clients.

You can always message me privately with any questions your may have.  I always encourage those that have questions to please reach out.

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CJ Woodruff, Owner The Fitness Trainer Academy
C.J. Woodruff
Founder / CEO,
The Fitness Trainer Academy Inc.

Carbohydrates Are Next!!!

In PART 3 of this series I will be discussing all the things you NEED TO KNOW about Carbohydrates.   Carbs may be one of the most confusing and controversial of all the macros, But you’re gonna have to wait….