The Fuss About Protein
Of the three macronutrients protein seems to be the one that gets the most praise, but not without some controversy. People still debate about: what’s the best source of protein, plant or meat? How much protein does the average person needs? Is it safe to consume more protein than you need? Will it damage my kidneys?
The answers to these questions seem to be relative. It’s difficult not to fall down a rabbit hole of information about this macronutrient. And while most people usually associate protein with building muscle, it serves such a tremendous array of function. For example, protein is involved in everything from hair and nail growth, bone maintenance, to producing neurotransmitters and digestive enzymes.
More Specifically, protein from food is broken down into its simplest forms which are Amino Acids. “Amino” means “containing nitrogen” (Essentials of Strength Training and Conditioning, p.206). Relatively speaking, we can still function on a diet that is low in carb and fat. Our bodies can generate glucose through a process called Gluconeogenesis. Your body can also create fat through another process called Lipogenesis.
However, things are a different with regard to protein. There are two classes of Amino Acids: Essential and Non-Essential Amino Acids. Our bodies can create certain amino acids through chemical processes. However, Essential Amino Acids (EAA) that can only comes from food.
Fun Facts About Protein
-1 gram of Protein = 4 kcals
-There are 21 Amino Acids (AAs) in total
-11 nonessential AAs and 9 Essential AAs (Table below)
-There are 3 Branch Chain Amino Acids (BCAAs): Leucine, Isoleucine, and Valine
-BCAAs make up roughly 35% of the body’s muscle protein
-It is the only macronutrient that contains nitrogen
-Can be synthesized into specific hormones (ex: insulin) and neurotransmitters (serotonin)
-The antibodies we create to ward off infection and disease are made up of protein.
(Advanced Sport Nutrition, p. 28)
Most people are familiar with the role that protein plays in building muscle, but it does lots of other things! To start, proteins can be broken down into two categories: Working Proteins and Structural Proteins.
In short, Working Proteins produce hemoglobin, enzymes and hormones, and also form antibodies. Structural Proteins make up cell structures, and help develop, repair and maintain tissues including muscles, tendons and ligaments, skin, and even hair and nails. (Advanced Sport Nutrition, p. 30)
Essential Vs. Non-Essential Amino Acids
And don’t be fooled into thinking that “non-essential” means that we don’t need it! All it means is that the body can combine different amino acids to create certain other ones. Essential amino acids, on the other hand, are a class that the body cannot create. That said, Human metabolic processes require both classes of amino acids.
Protein Metabolism and Protein Synthesis
First, after you eat it, protein is broken down into polypeptides, which are basically small protein molecules. Second, after a few more steps, those polypeptides are broken down into individual amino acids. Thirdly, those AAs are absorbed into the blood, usually ending up in the liver and turned into whatever proteins the body needs
Some will tell you that consuming certain proteins will help repair/grow specific organs/tissue. But be weary. For example, certain supplements advertise that they help you grow healthy hair and nails, because they contain Gelatine. And since hair and nails are made primarily of gelatine, eating gelatine will help you grow strong hair and nails. But no.
Sadly it’s not that simple, “eating hair and nails does not encourage optimal synthesis of hair and nails”. (Advanced Sports Nutrition, p.31) Yet another reason to spend your money on quality food, and not gimmikey supplements. In order to understand that further, let me tell you about protein synthesis.
Protein Synthesis
This is a term that you often hear around the gym. I, as well as others will tell you that it’s the reason why tissue repair/growth happens! But what’s the deal with it and how exactly does it happen? WARNING: FUN SCIENCE TALK ABOUT TO HAPPEN!!!
Protein synthesis happens primarily in the liver. Understandably so, protein needs some sort of a processing plant. As such, in the liver, protein and amino acids are combined, broken apart, recombined, and synthesized into whatever is needed.
More specifically, protein synthesis involves two main processes: Transamination and Deamination (not to be confused with Damnation!).
Transamination involves taking the nitrogen from one amino acid and using it to create another amino acid. Deamination involves the removal of an amino group from an amino acid, and converting it to ammonia. Whatever amino acids are left, after the body’s protein needs are met, get deaminated.
What’s left after deamination is a carbon structure that is reconstructed into either fat or glucose. If it’s fat it’s then stored into adipocytes (fat cells). And if it’s glucose it’s used for energy. Deamination also creates some ammonia, which is then turned to urea, and well…you pee that out.
Quality of Protein
There are two ways to determine the quality of protein:
-1) Calculate how much nitrogen is retained after the protein is broken down. More nitrogen retained = more protein utilized which means the protein is higher quality.
-2) Compare the protein against the albumin in eggs (albumin has an almost perfect distribution of EAAs)
Here’s a of different foods that shows the percentage of retained Nitrogen, after they’re digested
-Whey Protein: 96% Cheese: 84%
-Whole Soybean: 96% Rice: 83%
-Chicken Egg: 94% Fish: 76%
-Soybean Milk: 91% Beef: 74%
-Cow Milk: 90% Tofu: 64%
Here’s a list of foods with protein quality compared to a whole chicken egg
-Whey Protein Concentrate: 104
-Whole Chicken Egg: 100
-Cow Milk: 91
-Beef: 80
-Casein Protein: 77
-Soy: 74
-Wheat Gluten: 64
As you can see, in both cases, eggs rank pretty high in terms of protein quality. I’m personally a huge fan of eggs. I know…every year there’s a new damn study that says something about eggs. Eggs are bad. Eggs are good. Only eat x number of eggs/week etc. I have seen more evidence to show that eggs are not harmful when consumed regularly (2-3 eggs/day). Of course all things being equal and you’re not allergic, told not to by your doctor etc.
How Much Protein Do You Need?
The daily requirement for the average person is between 0.8g and 1g of protein/kg of body weight. This means that a 68kg/150lbs person requires roughly 55g-68g of protein/day.
Athletes need about twice as much since they have more lean mass to feed. They also have a higher amount of tissue breakdown, because of training hard and often. So they need about 1.4g – 1.7g of protein/kg. For example, a 68kg/150lbs athlete requires about 95g – 122g of protein/day.
I’ve also had clients ask me “What happens if I eat more protein than I need?” A healthy person will be fine. the body will process the protein and get rid of what it doesn’t need. And it should also be noted that the recommended daily intake (RDI) changes as we age.
Factors such as your age, activity level, and sex, affect how much protein your body needs. I was surprised to learn that our protein requirement goes up after age 40 for a couple of reasons. First, we need it to rebuild tissue because breakdown occurs at a faster rate than the body can regenerate. Second, our bodies extract less protein/gram. In a sense, we need to increase the saturation of protein to make sure the body can take what it needs.
Protein requirements for tissue repair, metabolic, and hormonal processes pretty much cap out at those numbers listed above. Extra protein will get deaminated. Deaminated protein is excreted in urine, converted and stored as fat, or used for energy.
What About Plant Protein?
Plant based diets are all the hype right now, and why not? With films like Game Changers and What the Health, promoting vegan diets and slamming meat consumption and the meat industry. The meat industry is accused of funding false research and lobbying for high meat consumption. Because lord knows vegan supplement companies don’t fund those films and their products
In particular, I find the way in which these films involve so much fear mongering, very troubling. They base their claims on data that is cherry picked and manipulated. And when someone isn’t good at reading statistics, and understanding research, it can all be daunting.
I won’t get too deep into it, but the film Game Changers is particularly heinous. I think anyone who saw the movie should watch this play by play breakdown by Layne Norton and Holly Baxter. Norton has a PhD in Nutrition Science, and Baxter is a registered Dietician. Both are more than qualified to explain the problems with the film
Now let me make it clear, I love veggies, legumes, grains etc. I’m Lebanese/Syrian for god’s sake, have you looked at the foods we eat?? It’s all chickpea this, lentils that, eggplants, tomatoes, potatoes etc. And I definitely believe that people need to increase their intake of fresh vegetable. Aside from providing us with tons of nutrients, vegetables are amazing sources of fibre.
Furthermore, I also believe that a lot of people should reduce their intake of low quality meats. The main culprit here being fast food meat, and highly processed supermarket meat.
That being said, for reasons already mentioned, the quality of protein in plants is less than that in meat. Please feel free to try and change my mind by presenting it me with credible research data.
In any case, here’s a list of some of the best plant based foods that are a source of protein:
Final Thoughts
I love wraps…preferably as Shawarmas or Burritos. Anyway, protein is an important macronutrient. As I mentioned, its role goes beyond building and maintaining muscle. Protein is necessary for maintaining healthy cells, organ, and sustain various metabolic functions. Also, I don’t know about you, feel more full and satisfied after a protein rich meal.
What I find interesting is that most people are only interested in protein’s role in weight/fat loss. Proponents of Ketogenic, Paleo, and Carnivore diets swear by it as if it has some magic properties. But it doesn’t. No macronutrient is a magic pill. Protein is an important macronutrient that should be part of any healthy diet.
I am most concerned with overconsumption of protein when it starts to overshadow the other nutrients. Namely, that you really should be getting enough fibre in your diet, and not just loading up on meat and dairy. Studies show potential health risks associated with diets consisting mostly of animal protein.
But I also want to caution about trying to get most of your protein from plant sources alone. Besides soybeans, your body can only extract about 1/3 of the protein in vegetables/legumes/grains. And for the most part plant products don’t usually provide you with complete proteins. Not to mention that plant foods usually also provide a much bigger dose of carbs and fats.
I always come across posts on social media of people and their “protein bar” recipes. Then I go through it and it’s primarily sugar and fat! Something sweet like honey/maple syrup/ some kind of agave and 5-6 different kinds of nuts! Oh and let’s not forget chia seeds, hemp seeds etc.
Now I personally don’t have anything against those foods. In fact, they are DELICIOUS! But they are NOT protein bars! I wish people stop calling them that! And don’t fool yourself into thinking they are. Look at the ratios. A true protein bar should have at least a 2:1 protein to carb ratio. Those bars are usually more like 15g fat, 12 grams carbs, 5 grams protein. And remember that your body extracts about 2g out of those 5g of protein.
There are definitely different strategies to incorporate more protein into your overall diet (whatever that looks like). And a good nutrition coach can help you develop a plan that is suited for you. At the end of the day you want something that is nutritious and sustainable for you.
Think about it and hit me up with any thoughts, questions, or comments. Peace!
Sources:
-Jeukendrup, Asker. “Sports Nutrition From Lab to Kitchen”, Maidenhead: Meyer & Meyer Sport (UK) Ltd., 2010
-“Essentials of Strength Training and Conditioning”, 3rd ed. Baechle & Earle. National Strength and Conditioning Association. U.S. 2008
-Protein for Life: Review of Optimal Protein Intake, Sustainable Dietary Sources and the Effect on Appetite in Ageing Adults https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5872778/
-Protein “Requirements” Beyond the RDA: Implications for Optimizing Health https://pubmed.ncbi.nlm.nih.gov/26960445/
-Protein – Which is Best? https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3905294/
Dietary Protein Sources and Muscle Mass over the Life Course: The Lifelines Cohort Study https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6212815/