Is All Protein Created Equal?
By Julia Kirkpatrick, MS
Protein is a necessary building block that helps your muscles produce force to propel your sprint up and down the field or court. But does your 8g of protein in your peanut butter & banana sandwich work the same as the 10g of protein from turkey lunch meat? What about the protein in your cheese stick versus your protein pasta? Does protein type matter if you are an athlete or not?
This article provides you with the answers!
At this point, it’s common knowledge that protein is a necessary and healthy part of your diet. Protein is the building block for tons of structures in our body including hair, nails, skin, muscles, and much more! So, what’s the big deal? It’s not THAT hard to get enough protein… is it?
Look at the back of your peanut butter jar. Most likely, the macro breakdown of this delicious snack will look something like this:
For one serving (equivalent to 2 tablespoons) it’s about…
15g of fat
6g of carbs
8g of protein
otal calories: 190
8 grams of protein?! Obviously, peanut butter is not only tasty, but makes a perfect food option for carbs, fat, AND protein! Throw it on a banana and you’ve got yourself a well-balanced meal… right???
Now, look at the nutrition for your mid-day cheese stick snack:
One cheese stick looks something like:
6g of fat
1g of carb
7g of protein
Total calories: 80
Basically, the same amount of protein which means:
Peanut butter is just as good as eating a cheese stick?
First, what is protein?
Protein is made up of individual amino acids, which you can think of as Legos.
Different Legos can be strung together to make different structures and are in constant flux. These ‘Legos’ are constantly being built up, broken down, and rearranged which ensures that damaged proteins are discarded, enzymatic processes can take place, and energy is provided!
As a bonus, the body can synthesize (create) a lot of these individual amino acids on its own (termed: nonessential amino acids). However, some of these building blocks must be consumed exogenously (through your diet) because our body cannot create them on its own.
Out of the 20 amino acids that make hundreds of different combinations, 9 of them cannot be created by your body (these are referred to as essential amino acids)!
Imagine building a Lego house and you’re almost done but you’re missing one piece to complete the roof on the house. Without this Lego, the structure won’t be complete, and you’ll be stuck with a leaky house.
When we think about this in terms of eating, the big question is: how do you avoid that leaky roof?
Let’s consider a protein checklist:
A. Am I consuming a quality protein? (i.e. – how many essential amino acids are in my protein?)
B. How much of this protein source has calories that come from the other macronutrients?
C. Does this protein also provide key micronutrients/phytonutrients?
Think of quality protein like a Tetris game. You have a bunch of different blocks and you need them to fit together perfectly to continue clearing lines. In our case, the goal is to meet the needs of all the essential amino acids which is key for maintaining and building muscle, since our muscle is primarily made from these amino acids.
High quality proteins have a balanced amino acid profile that exactly matches individual essential amino acids requirements in our body. With all the correct Tetris pieces and placement, you have your best chance at continuing to play the game! In this case, high quality proteins make it possible to maintain muscle mass and build more! Similarly, bioavailability is another contributing factor to protein quality. Bioavailability refers to the digestibility of proteins. Low digestibility means less building blocks to use for muscle growth!
Think of it this way: just because the label says it has 12g of protein, it doesn’t mean all 12g listed are QUALITY protein and therefore will be absorbed and put to work by the body the way you want!
HIGH protein quality foods include dairy, poultry, and animal products.
Think the protein present in eggs, milk, casein, whey, cheese, meat, fish
LOW protein quality foods include plant-based protein.
Think the protein present in nuts, beans, peas, rice, bread, wheat
Suppose your options for protein are a handful of nuts or a chicken breast. Nuts are often advertised as a high protein snack food, and you love to eat nuts. Chicken can be dry and hard to take on the go anyhow!
Let’s say you are aiming for 25g of protein in that meal:
25g of protein from a grilled chicken breast ~ 125 calories
25g of protein from plain almonds ~ 675 calories
This is almost 5.5 times the number of calories!
While nuts DO contain protein, it is important to remember that protein density (think: how much protein am I consuming relative to the fat and carb content) differs widely among foods.
It is crucial to meet protein needs while also satisfying our daily caloric needs, which becomes increasingly difficult - if not impossible - with low protein density foods.
In a similar sense to protein density, we can also think of nutrient density when consuming protein. Different protein sources will contain varying levels of vitamins, minerals, and phytonutrients – organic compounds that are not essential to an individual’s diet, but more an extra health bonus.
Both animal and plant-based proteins offer an array of key vitamins and minerals such as: calcium, iron, vitamin A, riboflavin, niacin, and iron.
However, it is important to consider the co-consumption of protein and nutrients. For example, plant-based proteins are often high in fiber, which is a super important nutrient in our diet. However, high fiber content has been shown to reduce the digestibility of protein which can reduce the number of building blocks we have!
Here’s another example with milk: the fat in whole milk increases muscle protein synthesis response when compared to skim milk, which has the same amount of protein, but without the fat! So, while both animal and plant-based protein provide key nutrients, there are some tradeoffs to consider with each.
This brings us back to the original scenario at hand: cheese sticks and peanut butter – are their protein contents equal?
Let’s go through the protein check list again:
A. Protein Quality – peanut butter is made from nuts, which is a LOW quality protein; cheese is a dairy product which is a HIGH quality protein – this means more protein available to build lean tissue!
B. Protein Density – for the same amount of protein, peanut butter has over 2x the number of calories that string cheese does!
C. Health Benefits – both provide sources of calcium and vitamin A!
And…. The results are in! It’s beginning to look like they may not be equal after all!
Some foods WILL have the same amount of protein, but this does not mean that all protein is equal in quality or usage, which becomes increasingly important when considering sports performance.
If your diet mainly consists of low-quality proteins, you are consuming a considerable amount, but have a low return on your investment! As the saying goes: quality over quantity!
Implications for sports performance?
Say you’re a high school sophomore, eventually hoping to make it D1 in soccer. You’re working your a** off during practice, drilling, conditioning, and lifting a few times per week. Now what’s all this chat about protein and does it affect ME?
Different individuals have different protein requirements based on body composition, age, and… training – hello to all you athletes!
This means that mom and dad will probably have a plate that looks a little different than YOU – and for good reason!
Let’s find out why…
As you can imagine, the demand of sport is very different than the demands of everyday life and perhaps the working parent. As an athlete, it’s not uncommon to have a half to full time JOB in sport, where you could be putting in 20 to 30 hours of HARD training. This might include practice, recovery sessions, conditioning sessions, lifting, and games. This puts a much larger stress on the body than going to a day job and maybe hitting the gym for 3 to 5 hours a week.
Athletes are putting in hours of work to accomplish a very specific goal, which requires specific preparation. Lots of training (and life) stressors means the body will be broken down much more than a non-athlete, where their training load might look 5 to 6 times smaller.
When the body is broken down, it needs those building blocks to rebuild itself, PLUS a few extra building blocks to ADAPT and grow STRONGER.
Would it make sense to consume enough fuel to JUST recover? No way! The goal of an athlete is not just recovery but adaptation. Adaptation drives progress and prevents stagnation. So, not only do we need to replace lost protein due to general turnover of our hair/skin/enzyme function, we also need enough protein to recover from hard training stressors and have extra to build new structures!
Here is a simple equation to remember:
Sufficient QUALITY protein = ↑ building blocks leading to = ↑ lean tissue (muscle) = ↑strength = ↑ jump height, power, speed and ↓injury risk
Remember, muscle is composed out of essential amino acids that our body is not going to produce on its own! In other words: it’s OUR responsibility to provide the raw material for building lean tissue. Muscle is the key that unlocks athletic potential: higher jumps, more power, and DECREASED risk of injury! Sounds like a pretty good deal to me!
On the other hand… “I’m a non-athlete”: Since my weekly training volume is 5 to 6 times lower does this mean I need protein amounts that are 5 to 6 times smaller?
Nope!!! Protein demands are not linear in nature. However, it is important to understand that there are distinct differences between a healthy person who casually exercises a few times a week and, and an athlete that is TRAINING for a specific goal.
Protein is still the foundation for all human structures, so you still need plenty of it! However, you might not need as much as a full-time athlete.
· Protein quality refers to the amount AND digestibility of essential amino acid - remember these are our building blocks
· All protein is not equal protein: high quality protein delivers the correct TYPE of building block for muscle growth and repair
· Muscle growth and recovery can only occur if we have puzzle pieces that fit together with one another
1. Jeukendrup, A., & Gleeson, M. (2019). Sports Nutrition (Third Edition). Champaign, IL: Human Kinetics
2. Mathai, J. K., Liu, Y., & Stein, H. H. (2017). Values for digestible indispensable amino acid scores (DIAAS) for some dairy and plant proteins may better describe protein quality than values calculated using the concept for protein digestibility-corrected amino acid scores (PDCAAS). British Journal of Nutrition, 117(4), 490–499. https://doi.org/10.1017/S0007114517000125
3. Wolfe, R. R., Baum, J. I., Starck, C., & Moughan, P. J. (2018). Factors contributing to the selection of dietary protein food sources. Clinical Nutrition, 37(1), 130–138. https://doi.org/10.1016/j.clnu.2017.11.017
About the Author:
Julia holds a M.S. in Sports Science and Coach Education from East Tennessee State University and a B.S. in Kinesiology with a concentration in Exercise Science from Temple University. During her time at ETSU, Julia worked as the Assistant Strength and Conditioning Coach for the Women’s D1 Volleyball team and headed their sports nutrition. She also worked as the Head Strength and Conditioning Coach at a local college in Tennessee for their Track & Field team.
Julia’s main passion is bringing an evidence-based approach to training and nutrition practice. Her time spent around collegiate athletes highlighted the gap between real-world practice/understanding and science; enter Relentless Athletics. After working with a variety of athletes and online diet clients, Julia knew there was a hole that needed to be filled – specifically for females. She saw that there was an absence of reliable sources for these individuals to gather information to help develop their athletic ability. Relentless offered the perfect community for Julia to spread her knowledge and help build STRONG foundations for females through nutrition education and training.
In her free time, Julia competes in powerlifting and weightlifter recreationally. She holds the Pennsylvania Junior State Record in the bench press in the 72 kg weight class.