Updated: Mar 7
Nowadays, you can find "high protein" products in every supermarket, shop you go to. You may hear people in your gym talking about protein intake, or Instagram influencers promoting protein brands.
Is protein a marketing object, or is protein really important for you ?
What is a protein ?
The Harvard School of Public Health defines protein as folllowing :
' Protein is found throughout the body—in muscle, bone, skin, hair, and virtually every other body part or tissue. It makes up the enzymes that power many chemical reactions and the hemoglobin that carries oxygen in your blood. At least 10,000 different proteins make you what you are and keep you that way.
Protein is made from twenty-plus basic building blocks called amino acids. Because we don’t store amino acids, our bodies make them in two different ways: either from scratch, or by modifying others. Nine amino acids—histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine—known as the essential amino acids, must come from food. '
Ok so protein is composed of 20 amino acids (molecules that combine to form protein) working in a chain. Those chains are important parts of every structure in our bodies (from hair to bones). To make up a protein we need to get those amino acids. Some of them are produced by our bodies and some must be found in food because our bodies don't produce them. But is that possible ?
Can I find all the protein I need in food ?
To answer this question it is important to make the difference between essential amino acids and non essential amino acids that make up protein.
Out of the 20 amino acids that exist there are 9 essential amino acids (histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine). Essential meaning that they are not produced by our bodies and so need to be found in food.
And so there are 11 non essential amino acids produced by our bodies, which means they don't need to be consumed when eating.
There are 2 ways to get the essential amino acids you need.
You can eat incomplete sources of protein, which means consuming food that contains some of the 9 essential amino acids. By eating a large variety of incomplete sources of protein you can make up a complete source of protein.
Legumes (beans, lentils, peas), nuts, seeds, whole grains, vegetables are incomplete sources of protein.
A good knowledge of the composition of these ingredients will help you reach the 9 amino acids intake that your body needs.
Incomplete sources of protein are part of vegetarian or vegan diets for instance and represent a natural, efficient source of protein.
For example you can have food that contains histidine, isoleucine, leucine and lysine + food that contains methionine, phenylalanine, threonine, tryptophan, and valine and so have the all 9 amino acids you need to make up a protein.
Complete sources of protein, such as fish, poultry, eggs, beef, pork, dairy and whole source of soy (edamame, tofu) are a great alternative to get all of the 9 essential amino acids needed in an easier way, if your diet allows you to.
So then why do you see so many people having protein shakes or bars when it seems possible to get all the protein needed in natural food ?
Non natural sources of protein
There are many different reasons why people use non natural protein sources.
The first of them is convenience.
The Harvard School of Public Health specifies that 'The Recommended Dietary Allowance (RDA) for protein is a modest 0.8 grams of protein per kilogram of body weight' which sounds like a fair attainable amount. However this is the minimum that needs to be eaten everyday to remain healthy and not suffer any illness.
The optimal amount of protein needed is about 1.6 to 2.2g of protein per kg of bodyweight depending on the study (for example a woman that weights 55kg would need about 55*1.8= 99g of protein a day). Which makes it slightly more difficult to reach. For that reason, protein shakes or bars can be a good alternative.
Also, most of the non natural sources of protein are flavoured. People craving sugar who want to limit their daily intake may find the sweet flavours more enjoyable. Eating a huge amount of natural protein, such as chicken or plants might lead to boredom and the idea of having something sweet but still healthy can be a good treat and help people follow their diet.
However, attention must be paid to composition when you are about to choose a protein shake.
In fact The Harvard School of Public Health specifies that 'Available evidence indicates that it’s the source of protein (or, the protein “package”), rather than the amount of protein, that likely makes a difference for our health.'
B vitamins, essential fatty acids, zinc and iron, vitamin E and fiber come along with protein. Some of the non natural sources of protein may not include them so special attention must be paid to ingredients when you are about to make your choice.
Protein, an essential intake
To be clear, protein must be part of your daily intake and the amount varies depending on your physical activity.
No less than 0.8g per kg of bodyweight and no more than 2.2g must be consumed. It can come from complete (chicken, eggs, poultry) or incomplete sources of protein (nuts, seeds, whole grains) and as much as possible from a natural source of protein.
Non natural sources of protein are good to complete and help you reach your daily intake but can not substitute natural sources.
Don't forget to pay attention to micro nutrients that come along with protein and keep a large variety of protein intake.