What is protein?
Proteins are macronutrients that participate in the renewal and construction of muscles, skin appendages (hair and nails), bone matrix and skin. “Amino acids are the pearls of a necklace that form protein. »
Indeed, a protein corresponds to the assembly of several amino acids. These are the elements that make up proteins. There are a total of 20 amino acids, 9 of which are considered essential. These cannot be synthesized by the body, they must therefore be supplied through your diet.
What are the 9 essential amino acids?
- Valine
- Isoleucine
- Leucine
- Histidine
- Tryptophan
- Methionine
- Phenylalanine
- Lysine
- Threonine
- Structural role: this is their fundamental role. Proteins make up a very large number of structural elements of our body such as cell membranes, collagen, connective tissue, bones, muscle mass, etc.
- Catalytic role: numerous reactions take place every second in our body. It is proteins, in the form of enzymes, which ensure the proper functioning of these reactions which are important for our health: digestion, absorption of nutrients, production of energy, etc.
- Role in muscle contraction: proteins make up the fibers that make up the muscle. A shortening of these fibers allows muscle contraction.
- Role in the transport of molecules in the blood: for example, hemoglobin is a protein which will allow the transport of oxygen in the blood while transferrin will transport iron. There are many other carriers.
- Protective role of the immune system: antibodies are proteins which will detect all substances foreign to the body (antigens) and trigger the mechanisms for their elimination.
- Regulatory role of the endocrine system: many hormones such as insulin which are involved in the regulation of blood sugar are proteins. Hormones can be synthesized by different organs to ensure a regulatory function for the homeostasis of our body (they maintain the body in a stable and viable state).
Energy role: proteins have a slight energy role. Indeed, in the event of a lack of energetic macronutrients such as lipids or carbohydrates, proteins may be broken down into energy. 1 g of protein provides 4 kcal just like carbohydrates.
What foods are rich in protein?
There are two food sources of protein:
Animal proteins.
They contain all the essential amino acids in large quantities. They are found in all meats (red meats, chicken, turkey, etc.), fish (salmon, tuna, etc.), eggs but also in dairy products (milk, cheese, yogurt).
Animal protein contents per 100 grams.
- Cheese: 22 g
- Meat, fish, egg: 18 g
- Fresh cheese: 8 g
- Dairy: 6 g
- Yogurt: 4 g
- Milk: 3.5 g
Plant proteins.
Cereals (oats, rice, wheat, etc.) as well as legumes (lentils, peas, soya, etc.) are excellent sources of plant proteins, although they may be deficient in certain essential amino acids.
- Lentils: 25.4 g
- Split pea: 22.8 g
- Chickpeas: 20.5 g
- Flour: 10 g
- Raw starch: 10 g
- Bread: 8 g
- Cooked starch: 2 g
- Fresh vegetables: 1 g
- Fresh fruit: 0.5 g
Consuming meals that include a sufficient amount of protein is also beneficial because the digestion process of this nutrient is slow. Incorporating foods with a high protein content into your meals therefore allows you to achieve a more lasting feeling of satiety.
How much protein do you need?
It is important to provide good quality protein daily and in adequate quantity for your daily needs. For a non-athlete reference adult, ANSES recommends that protein intake covers 10 to 20% of the total daily energy intake with a minimum of 0.83 g of protein/kg of body weight/day. However, these are reference values, corresponding to a minimum daily requirement for a healthy adult and not an ideal to achieve. As far as athletes are concerned, it all depends on the type of physical activity practiced and your goals. However, it is recommended to consume between 1.2 and 2 grams of protein per kg of body weight per day. Such a contribution allows optimal reconstruction of muscle fibers damaged during exercise.
For example, a 70 kg man will need to consume between 84 (70×1.2) and 140 (70×2) grams of protein per day.
How to distribute protein consumption in your diet?
It is advisable to distribute your total protein intake across all your meals to promote better absorption and digestion. In certain populations at risk such as the elderly, it may be recommended to provide the majority of daily proteins in one dose in the morning.
What is whey protein?
Whey, also called whey protein or whey, is a protein extracted from cow's milk. It is rich in essential amino acids and ideal for muscle growth. It is the food supplement most used by athletes for muscle repair and construction thanks to its rapid assimilation. Whey should therefore be taken around training. Its low lactose content makes whey protein easily digestible and compatible with people with lactose intolerance.
Should you follow a high-protein diet?
It can be useful to use a high-protein diet if you want to increase your muscle mass, coupled with intensive sports training. Paradoxically, it is also common to resort to a high-protein diet when you want to lose weight. In fact, proteins, along with fiber, provide a quick and lasting feeling of satiety. However, be careful, the best way to lose weight healthily and sustainably is to eat a varied and balanced diet. Additionally, know that there is no point in consuming more protein than your body needs because any excess will be eliminated and not used to repair your muscles. Protein is only useful for bodybuilding, true or false? Fake. Protein is an essential nutrient whatever your goal. Athlete or not, you must consume proteins in order to avoid wasting your muscle mass but also potential health problems. However, taking protein food supplements (whey protein, protein bars, etc.) is actually more useful for athletes who want to increase their muscle mass and have access to proteins with faster assimilation.
What is casein?
Casein is a milk protein like whey. Milk contains 80% casein and 20% whey. It differs from whey protein in its ability to be digested more slowly by your body. Therefore, the time of consumption of this protein is different to maximize your muscle gains. Casein helps fight muscle breakdown and should ideally be taken with snacks or before sleeping. On the contrary, whey is conducive to muscle building and should be taken around training.
In summary.
Proteins play essential roles in the proper functioning of our body. There are 2 types of proteins: plant proteins and animal proteins. ANSES recommends consuming 10 to 20% of total energy intake in proteins for a reference adult and 1.2 to 2 gr/kg of body weight/day for athletes. It is advisable to spread protein consumption throughout the day.
