Protein 101: The Science Behind the Macronutrient

Protein has long been regarded as one of the most important components when it comes to crafting a physique and improving recovery. From the Golden Era when Arnold stepped on stage till date, the importance of protein has never been undermined. But just how crucial is protein to both maintaining your health and achieving your fitness goals. Here, you can read the science behind it and decide for yourself whether it deserves the importance given or it’s simply over-hyped.

Want 18-inch sleeve-ripping biceps? That might be a bit much, but if you’re here to craft a body of symmetry and that resembles a demi-god, then you’re in the right place. As a painter perfects his nimble-fingered art with brushes, a bodybuilder crafts a physique with unwavering focus and resilience. One of the tools a fitness enthusiast polishes and sharpens along his journey is ‘proper nutrition’ along with an effective ‘resistance training’ program. Whether you are new to the gym or a seasoned lifter you’ve heard everyone talk about the golden ticket to packing on some lean muscle mass. NO! I’m not talking about juice/gear (steroids). I’m talking about the one sitting under the spotlight of proper nutrition, the ever-famous ‘PROTEIN’. Is protein over-hyped? Or does it deserve to be treated as the foundation of a solid physique?

No one loves a meathead! If all you can do is move a bunch of weight, it won’t do you much good. Here is everything you need to know about protein so you can flaunt your BRAIN GAINS along with your biceps. Better yet? Become a real gym bro and save a newbie from downing countless protein shakes and struggle to break through their first plateau.

What is protein and how much do I need?

Ask any fitness enthusiast or healthy living expert and they will tell you that protein is the building block of your body and its muscles. To drive this point home, even its origin, ‘protein’ comes from the Greek word ‘Proteos’, that translates to ‘primary’. So, in its entirety what is protein? And how do I know I’m getting enough? Protein is one of 3 essential macronutrients.

The three macronutrients are proteins, fats, and carbohydrates. Each macronutrient is essential to sustain life. Next, micronutrients such as calcium, magnesium, phosphorus, sodium, and potassium are given priority. They are required in adequate amounts for an individual to be healthy and active.

Over the years, fats and carbohydrates have received a bad reputation for no fault of their own. They are essential components of a healthy diet and should not be neglected. However, proteins are clearly the hero when it comes to benefits and functions within the human body. Let’s take a closer look at protein.

whole eggs

Do you know how many calories are there in a single gram of protein?

Calories are units used to measure energy. If you are a numbers person, then you will be glad to know that one gram of both proteins and carbohydrates have 4 calories each. Fats, however, have 9 calories per gram and hence gain a bad rep. Eating various sources of fats which are processed and packaged (trans-fats) rack up the calories quickly and provide no nutritional value. But healthy fats are required for the smooth functioning of your system and maintaining bone health.

Carbohydrates can be consumed easily and are broken down into glucose for a burst of energy. Excess numbers lead to storage in the liver, with the help of insulin it gets converted into fatty acid. This acid finds its way throughout your body to store itself as fat in adipose tissue. Protein, on the other hand, does not find itself on your hips and thighs. In fact, a protein-rich diet is known to keep you fuller for longer, thus helping you eat less. Ultimately this translates to a fewer number of calories consumed and leads to weight loss.

What are proteins made of?

This section is for the nerds and anyone who wants to know ‘what are proteins made of’. Best put on your lab coat, on a chemical level, protein is composed of nearly 20+ amino acids. These compounds are made up of oxygen or sulfur, carbon, and hydrogen. Protein is the building block of the muscle and amino acids are the building blocks of protein. When protein is broken down by the body it is used as fuel for muscle mass. It also helps the bodies metabolism. Therefore, you see fitness coaches advocating for muscle building and growth. Maintaining muscle on your frame burns a significantly higher number of calories than carrying fat. In theory and reality with a proper diet, building muscle can help you lose fat.

Types of protein

To simplify understanding, protein can be broken down into complete protein and incomplete protein. Keep reading to know their differences.

complete sources of protein
Complete Sources of Protein

Complete sources of protein

Protein sources comprise the 9 essential amino acids required by the body to build and repair muscle tissue. A complete protein is found mostly in animal foods such as fish, meat, eggs, poultry, and dairy products. Vegetarians may find it slightly difficult to acquire complete proteins in their diet unless they consume certain foods or have combinations of incomplete protein sources. Vegetarian complete protein sources are mainly quinoa and soybean.

Incomplete sources of protein
Incomplete Sources of Protein

Incomplete sources of protein

As the name suggests, these kinds of proteins do not have all of the 9 essential amino acids required by the body in a single source of protein. A combination of such food groups is essential to acquire the needed nutrition. These are mostly plant-based protein sources such as nuts, seeds, green peas, lentils, and the larger part of grains. Simple yet tasty meals that provide all 9 essential amino’s are legumes with seeds/nuts. Brown rice and green peas are a great combination if you have a voracious appetite. As a snack, you can opt for a bowl of yogurt and toss in a few walnuts.

What are the functions of protein?

Protein serves multiple functions in your body. There are some commonly known ones such as muscle growth and recovery. However, there are functions less known that are sure to make you re-think your diet.

1. Growth and maintenance

Let’s get the obvious out of the way first. Protein functions as the primary building block of your body. It enables you to grow and maintain tissues. For the most part, your body breaks down the same amount of protein it needs and uses to build and repair tissue. But, in times of illness, during pregnancy, high levels of activity, or while recovering from an injury the body demands and utilizes higher amounts of protein.

2. Causes biochemical reaction

Certain proteins are enzymes that aid in biochemical reactions. Weight watchers will be pleased to know that their effects impact your metabolism. Enzymes are also responsible for digestion and produce energy that your body needs to anything from lifting a pen to sprinting 100 meters. The main functions that your body depends on enzymes for are digestive, energy-producing, blood clotting, and muscle contracting activities.

3. Sends messages across your body

This goes to say that some proteins function as enzymes while others function as hormones. They carry messages to-and-fro your cells, tissues, and organs. The three main categories of hormones are:

  • Protein and peptides
  • Steroids
  • Amines

For the nerds, proteins and polypeptides comprise the maximum number of your body’s hormones. To name a few insulin, glucagon, growth hormone, and antidiuretic hormone.

4. Provides structure

Certain proteins are fibrous in nature. This attributes cells and tissues with their stiffness and rigidity. Some of the important proteins which comprise the elaborate framework in your body are keratin, collagen, and elastin.

5. Increases immune system health

When you consume the required amount of protein your body is able to perform one of its core functions. That is form immunoglobulins or antibodies in order to fight infection and invasion. Protein consumption directly impacts your immune systems capacity to protect you from bacterial and viral invasion.

6. Stores and transports nutrients

Everyone knows that your cells and organs receive nutrition and essentials through the bloodstream. What is less known is, proteins transport certain substances and store others based on its properties. Vitamins, minerals, blood sugar, cholesterol, and oxygen are some of the substances that are affected by protein transporters.

Ah! So there you have it. A complete understanding of how protein functions and why you need it. I could end the article here and head out to the bar. Of course, I’m talking about the squat rack and bench. Curious to know more? Well, if you insist.. Scroll below and read everything you need to know about amino acids, required grams of protein, and if there are any health risks of consuming high amounts of protein. Also, a peek into supplementation and what is available in the market.

resistance training and nutrition

Types of Amino Acids

If you’re a gym buff or a novice lifter you’ve probably heard about supplementing with ‘amino acids.’ Before you decide to grab a box on offer, are you sure you know everything there is to know about the supplement? Well, you’re about to find out! as touched upon earlier, amino acids are the building blocks of protein. Protein catalyzes chemical reactions in a cell and provides its structure. Further, it helps cells bind together into tissues (flex those guns). However, from 20 amino acids needed by your body, not all are equally important. Amino acids can be classified into the following.

Essential amino acids

From the 20 different amino acids needed by your body, only 9 are considered essential. These 9 amino acids cannot be made within your body. As a result, you need to acquire them through your….. ‘ding-ding-ding’ that’s right, DIET.

While naming them isn’t important, unless you are in a science nutrition course, you can skip this part. But if you are like me then you’re hungry for more than just a grilled chicken breast. So here goes, the amino acids are:

  1. Histidine
  2. Isoleucine
  3. Leucine
  4. Lysine
  5. Methionine
  6. Phenylalanine
  7. Threonine
  8. Tryptophan
  9. Valine

These essential amino acids are what make protein sources complete. They can be found in animal food such as fish, meat, and eggs. Vegetarians, need to consume a blend of protein sources or opt for quinoa and soybean. Not having an adequate supply of essential amino acids in your body can lead to complications in your nervous, reproductive, immune and digestive systems. Therefore, amino acids and protein should not be regarded as part of just the ‘Gym Bro’ regime.

Non-essential amino acids

These amino acid compounds can be made within your body and so you do not need to worry about them. However, there are certain amino acids that have conditional requirements and as such are called conditional amino acids. These amino acids are usually needed when the body is fending off illness. The supplementation may increase an already-present amino acid to the desired level or bring in the needed compound altogether.

Essential protein in meals

How much protein should the average man, woman, and child consume?

Now wouldn’t we all love just to see a number put out for us based on our gender? Afraid the answer isn’t quite that simple. Fortunately, however, your bodies protein requirement is as unique as you are. There are many factors to consider when gauging your optimal protein requirement. Some of the key contributors are your age, activity level, muscle mass, physique goals, and state of health. Your gender does not impact the amount of protein you actually require as much as the factors mentioned above.

Keep in mind activity level changes regularly, someone with a job such as a construction site worker or door-to-door salesperson requires more calories and protein than someone with a desk job. The recommended daily protein intake to maintain muscle mass is 0.8g per kg of body weight for sedentary people.

For athletes, on the other hand, protein intake can go up to 2g per kg of body weight. To induce muscle recovery and train optimally almost all professional athletes are required to consume protein supplements. Naturally, this is because getting them from food sources becomes difficult. However, as a layperson, if your diet does not contain sources of protein, you should include lean protein food sources. Additionally, consider supplementing with protein to meet your daily protein goals.

high levels of protein in meat

What are the adverse effects of too much protein?

There is a lot of unfair criticism blaming protein for a variety of health problems. One such example is kidney problems. There is data to prove that protein restriction for people with pre-existing kidney problems is helpful. In such cases, high levels of protein in your diet can lead to the formation of kidney stones and uric acid stones. However, there is no proof that shows protein as the cause of kidney damage in healthy persons. It has also been blamed for osteoporosis, which is bizarre as recent studies show that it can help fight the condition.

However, according to Montefiore Medical Center and The Albert Einstein College of Medicine, excessive dietary protein foods that demonstrate high potential renal acid loads can affect bone density. But, the consumption of alkali-rich foods (fruits vegetables, legumes, and nuts) can negate their effects.

Add these natural sources of proteins to balance your diet

When it comes to setting a healthy meal plan it is advised that 35% or more of your daily calories should come from protein sources. Eating meats, fish, eggs, and poultry are a great way to consume fewer amounts of food and meet your daily requirement. On the other hand, you can have milk-based foods, nuts & seeds, along with legumes and consume a slightly higher number of calories due to food combinations. Personally, I find eating egg whites to be the best way to meet protein intake while staying full. With 6 grams of protein per egg (take away 2 grams if you are removing the yolk), 10-12 eggs a day can make reaching your protein intake simple and easy. Not only is a great way to stay full but buying eggs don’t burn a hole into your pockets either.

Here are some of the best foods you should consider adding to your meal plan.

Protein Source Protein per 100G Calories
Boiled eggs 13 155
Chicken breast 31 165
Beef tenderloin steak 26 260
Pork belly 27 242
Lamb leg sirloin 17 272
Fish 25 144
kinds of protein

What kind of protein supplements exist?

As far as stigma goes, there are numerous myths that regard supplementing with whey protein as taboo and unhealthy. There still exists a false pretense that protein is required ONLY by athletes and bodybuilders alike. A dietary protein supplement can help you meet your dietary requirement in case you are falling short. It is extremely important to get the required amino acids, especially if you are a vegetarian. Doing so will help you protect yourself from chronic aliments and maintain your health. You can include a protein supplement in your daily routine without any particular timing. Bonus? It helps you feel fuller and prevents unnecessary snacking.


There are more protein powders on the market than people in your local gym (maybe a slight exaggeration). Protein powder varies in grams of protein per scoop. This can range from anywhere between 6 grams to 30 grams of protein per scoop. You need to be vigilant about it so that you can get one that fits your needs. Read, how to choose the right protein supplement for me? Before you make a decision.

You can also use protein powder as a binding agent or key ingredient in several dishes and treats. Take a look at some protein pancake, cupcake, brownie recipes. However, keep in mind that unflavoured protein works best if you are planning on adding it to your food. Otherwise, there are a plethora of flavors you can choose from offered by global brands.

You can opt for all-plant proteins, vegetarian, non-vegetarian, pea protein, and more based on your lifestyle and diet. It is important to consult with your doctor before you consider supplementing.


For an added cost you can buy pre-mixed and ready to drink protein shakes. There are a number of flavors and products available. Your local gym is likely to have a vending machine with a few options to try out. These are great when you are in a rush or squeezing in a workout during your lunch break.
Conversely, protein powders are great to carry when on-the-go. Add water or milk at a time just before you decide to drink it. You can throw in some berries and sliced fruits with oats in a blender and make a mean high-calorie smoothie along with a scoop of protein. For an added flavor drop a dollop of peanut butter. (Just remember to wash your shaker as soon as possible, you’ll thank me later).


Protein bars are the way to go if you have a voracious appetite. They help you feel fuller for longer and satiate a sweet-tooth craving. Protein bars can be bought in bulk and save you a little bit of money. I personally love the orange peel chocolate flavors. Certain protein bars also function as ‘meal replacement’ bars by being denser in calories and other essentials. So, you don’t have to skip the nutrition a complete meal offers when busy.

It is important to remember that protein supplements are meant to ‘supplement’ already existing healthy eating habits. They should NOT be treated as a substitute nor should they be used as an excuse to gorge on junk food. In some cases, they are okay to function as a plan B for a given meal if you do not have access to food while on the road.

What types of protein supplements are available?

Protein supplement types

There are a number of protein supplements that can help you meet your physique and dietary needs. No matter your taste, dietary restrictions, or allergies you can find a protein source that best suits you. All the various protein sources are mentioned here, however, the emphasis is placed upon whey protein.

1. Whey

Undoubtedly the most common source of protein in the industry. Whey is almost synonymous with protein. Whey is the liquid part of milk that separates during cheese production. After going through a number of processing steps it finally gets recognized as whey protein. The amount of processing strips away the fats and coagulation which leads to a smoother texture but almost bitter taste. As you’ve seen you can buy its variants known as whey isolate and whey hydrolysate.

Basically, whey protein contains anywhere between 60-90% of protein per 100 grams. On the other hand, whey isolate contains 95% of protein per 100 grams and whey hydrolysate contains a whooping 99% of protein per 100 grams. Naturally, the price of hydrolysate and isolate exceed that of standard whey due to the number of steps in processing and amount of protein available.

2. Casein

This is the water-insoluble protein that is extracted from milk. Milk, with respect to protein, contains 80% casein and 20% whey. Casein protein is thus hard to mix down in a shaker and is ideal for cooking with. It is slow digesting and makes you feel fuller for a lot longer. Casein protein is a great choice for people seeking to limit the number of calories they consume and eat less throughout the day. It can curb cravings and hunger pangs.

3. Soy

One of the few vegetarian proteins that contain all 9 essential amino acids. Usually made of soybeans that is turned into soy flour. However, some people have their reservations towards soy protein as they are usually genetically modified in order to produce commercial quantities.

4. Egg

When it comes to whole foods, eggs one of the best sources, they offer the highest protein digestibility. In addition, they decrease appetite as they keep you fuller for longer. However, egg protein powder is made from egg whites. This can lead to a decreased experience of fullness contributed to the lack of yolk. The research involved with egg protein is far less than whey and casein.

5. Pea

The ideal choice for people with allergies and those who are vegetarian. Pea protein is high in fiber and lacks only 1 of the 9 essential amino acids. A study conducted showed that people with high blood pressure experienced a decrease while consuming pea protein.

6. Brown Rice

Rice protein lacks research and is still considered inferior to whey. This is due to the fact that has low volumes of one amino acid.

7. Mixed Plant

Comprises plant sources to give you all the essential amino acids. Since they contain high amounts of fiber, they digest slower than animal-based proteins. It also limits the number of amino your body can utilize instantly post activity. Two or more of the following sources are mixed to give you mixed plant protein powders.

  • Brown rice
  • Pea
  • Artichoke
  • Hemp
  • Flaxseed
  • Quinoa
  • Chia seed

There you have it, a detailed list of the various sources of protein available. When choosing a supplement, be sure to check the carbohydrate to protein ratio. The number of carbs in whey protein varies among brands and requires caloric adjustments accordingly. Some sources may not be suitable if you are on a particular diet such as ketogenic or paleo. When it comes to crafting a physique worthy of admiration supplements won’t take you all the way. Eat clean, train effectively, rest adequately and consume protein-rich foods to maximize the benefits from training. For now, I’m off to get a killer pump! And remember, you can’t out-train a bad diet. Believe me, I tried!!

Danesh Engineer
Danesh writes on a broad spectrum of topics such as financial health, consumer goods, health & fitness, and on best protein sources about protein and their impact upon the human body. His passion for lifting weights sees him in the gym before and after his professional life. No one loves a meathead so he works out his mind here. Research, experience, and factual data helps Danesh flex his Brain Gains.


  1. […] sources of protein are needed by your body as they contain all the essential amino acids. Read Protein 101 for more information on amino acids and protein. A supplement that contains all essential amino […]

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