Protein – Everything You Need To Know

If you spend any time online, chances are that you’ve stumbled across a multitude of articles, ads, and products encouraging you to eat more protein. It’s easy to be lured into fetching marketing promises when you are unsure what’s actually behind the “protein” buzzword. This evidence-based guide will answer all the questions you’ve always asked yourself about protein, helping you to tell apart fact from fiction!

What is Protein?

Living without protein is impossible. You can find over 10 000 different proteins in the human body alone, many of which make up our bones, nails, and hair (1). Proteins consist of building blocks called amino acids, some of which our bodies can produce by themselves. Others, the so-called “essential amino acids”, we have to consume by eating food. (Want to learn more about amino acids? Click here)

This is where our nutrition comes into play. Protein is one of the three key macro-nutrients, besides carbohydrates and fats, that are part of a healthy, balanced diet. The proteins we consume are utilized to replace the proteins being broken down in our bodies, which is a continuous process. One gram of protein has 4 calories, the same amount of calories as one gram of carbohydrates does. Fat has more than twice as much calories with 9 calories per gram.

Why is Protein Important?

Because protein plays a key role in enzyme, hormone, and hemoglobin (a molecule responsible for carrying oxygen from your lungs to your organs) production, eating enough of it is important to stay healthy. Besides keeping the hair and nails strong, consuming an adequate amount of protein is also crucial for good bone health and osteoporosis prevention (2). In fact, protein makes up roughly one-third of our entire bone mass (3)!

Additionally, the human body uses proteins to build and repair tissue, such as muscle mass. Therefore, consuming sufficient amounts of the macro-nutrient is a non-negotiable for many athletes and fitness aficionados. Lastly, the evidence suggests that besides having positive effects on the stabilization of blood sugar levels, protein is the most satiating of all three macro-nutrients (4). This may explain the weight loss industry’s recent craze about high-protein products. Check out the graphic below for other roles that protein plays in the body!

Image: @LettuceVegOut

How Much Protein Do I Need?

Because of the important role protein plays in our bodies, you might be asking yourself whether you’re eating enough of it. Truth is, becoming protein deficient is highly unlikely, provided that you eat enough calories overall. How many people do you know that have been hospitalized for protein deficiency? Exactly, probably none! In general, it’s pretty difficult to consume less than the recommended minimum of protein ( 0.8 grams of protein per kilogram of body weight for sedentary adults, 5).

Nevertheless, you may want to eat more than the recommended minimum of protein, depending on your goal. Athletes, for example, require a higher protein intake due to high activity levels and for recovery purposes. The recommended amount for muscle maintenance and building lies between 1.6 – 2.2 grams of protein per kilogram of body weight (6). But once that threshold is passed, more isn’t always more… The research suggests that consuming bizarre quantities of protein, as the occasional bodybuilder may promote, is not necessary to build muscle and strength.

In general, there is no proven optimal amount  of daily protein intake. In a study conducted at Harvard “among more than 130,000 men and women who were followed for up to 32 years, the percentage of calories from total protein intake was not related to overall mortality or to specific causes of death. However, the source of protein was important” (1). So instead of hitting some numeric daily protein target, paying more attention to the quality of foods on your plate will have greater benefits regarding overall health and longevity.

Is Too Much Protein Unhealthy?

You’re probably wondering if consuming a lot of protein has any negative side effects. Perhaps people have warned you that eating too much of it is bad for your kidneys.

Despite its popularity, this myth is relatively easy to debunk. While a high-protein diet is indeed harmful for people predisposed to kidney disease, those with properly functioning kidneys need not worry about eating too much protein. Healthy kidneys are responsible, among other things, for processing the proteins we consume. Applying the myth in question to perfectly healthy people is like warning people to refrain from breathing too much in fear of lung failure.

However, eating “too much” protein can be unhealthy in a different regard. I urge you to not consider the macro-nutrient by itself, but also the entire food “package” you’re consuming it with. If the amount of protein you eat is unhealthy largely depends on where you’re getting it from!

Someone whose main sources of protein include red and processed meats, which are associated with an increased risk of cancer, is typically less healthy than a person who eats a variety of protein-rich plant foods (such as legumes and whole grains). While animal-based protein sources are often laden with saturated fats and cholesterol, their plant-based counterparts can boast with high amounts of vitamins, phytonutrients, minerals, and fiber. For healthy vegan sources of protein, check out the info graphic below!

Image: @TheConsciousPlantKitchen

Not to forget, consuming too much animal proteins (on a societal level) is detrimental to the environment because of the intensive factory farming necessary to produce large quantities of animal-based foods.

Key Takeaways

  • protein is one of the 3 important macro-nutrients
  • eating enough protein is crucial to ensure normal bodily functions
  • protein plays a key role in muscle building, maintenance, and recovery
  • there is no proven optimal amount of daily protein intake
  • focus less on the amount of protein you’re consuming and more on the quality of the entire food “package”



(2) Wallace, Taylor C. PhD Optimizing Dietary Protein for Lifelong Bone Health, Nutrition Today: 5/6 2019 – Volume 54 – Issue 3 – p 107-115
doi: 10.1097/NT.0000000000000340

(3)  Heaney RP. Effects of protein on the calcium economy. Nutr Asp Osteoporos 2006 Proc 6th Int Symp Nutr Asp Osteoporos. May 4–6, 2006, Lausanne, Switzerland. 2007;1297:191–197.

(4) Hermsdorff HH, Volp AC, Bressan J. O perfil de macronutrientes influencia a termogênese induzida pela dieta e a ingestão calórica [Macronutrient profile affects diet-induced thermogenesis and energy intake]. Arch Latinoam Nutr. 2007 Mar;57(1):33-42. Portuguese. PMID: 17824197.

(5) Rand WM, Pellett PL, Young VR. Meta-analysis of nitrogen balance studies for estimating protein requirements in healthy adults. Am J Clin Nutr. 2003;77(1):109–127. Available at:

(6) Willoughby DS, Stout JR, Wilborn CD. Effects of resistance training and protein plus amino acid supplementation on muscle anabolism, mass, and strength. Amino Acids. 2007;32(4):467–477. doi:10.1007/s00726-006-0398-7.

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