What are proteins?
Proteins are biomolecules shaped by different amino acids which put in different geometrical order can give different types of proteins for all their functions.
What are proteins functions?
Proteins are fundamental to the human body for all of their function but the main ones are:
- DNA: Proteins play a crucial role in the replication, repair, and expression of DNA.
- Cell structure: Structural proteins such as collagen and keratin provide support and shape to cells and tissues, forming the framework of the body.
- Enzymes: enzymes are proteins that act as catalysts in biochemical reactions, speeding up processes such as digestion and metabolism.
- Transporting molecules: Transport proteins, like hemoglobin, carry essential molecules and ions throughout the body, such as oxygen in the blood.
What are essential amino acids?
Essential amino acids are those that cannot be synthesised directly by the human body and we to assimilate through diet. They are fundamental in muscle protein synthesis and overall health. Here are the nine essential amino acids and their primary functions:
- Leucine:
- Stimulates muscle protein synthesis and aids in muscle recovery.
- Regulates blood sugar levels and stimulates growth hormone production.
- Isoleucine:
- Involved in muscle metabolism and energy production.
- Supports immune function, hemoglobin production, and regulation of blood sugar levels.
- Valine:
- Promotes muscle growth and tissue repair.
- Provides energy during physical activity and supports cognitive function.
- Lysine:
- Essential for protein synthesis, hormone and enzyme production.
- Supports calcium absorption and bone health, and aids in the production of collagen and elastin.
- Methionine:
- Essential for metabolism and detoxification.
- Helps the absorption of zinc and selenium, and is involved in tissue growth and repair.
- Phenylalanine:
- Precursor for the neurotransmitters tyrosine, dopamine, epinephrine, and norepinephrine.
- Plays a role in the structure and function of proteins and enzymes.
- Threonine:
- Important for collagen and elastin production, supporting skin and connective tissues.
- Plays a role in fat metabolism and immune function.
- Tryptophan:
- Precursor for serotonin, a neurotransmitter that regulates mood, sleep, and appetite.
- Involved in niacin (vitamin B3) synthesis, which is essential for energy production and DNA repair.
- Histidine:
- Precursor for histamine, a neurotransmitter involved in immune response, digestion, and sleep-wake cycles.
- Plays a role in the growth and repair of tissues, and the production of red and white blood cells.
What are the best protein sources?
This might sound like a question that everyone can answer with ease saying meat, which is not the best but for sure a good source, or eggs, which are de facto the best source, but why?
Look at this:
This is a representation of the relative biological value of different protein sources, where the clear winner is lactalbumin, also know as whey protein.
These values use egg proteins as a value of 100, so foodstuffs that provide even more nitrogen than whole eggs, can have a value of more than 100, another way to consider BV is to have the percentage of absorbed nitrogen, in that case we would have:
- Whey Protein: 96
- Whole Soy Bean: 96
- Human milk: 95
- Chicken egg: 94
- Soybean milk: 91
- Buckwheat: 90
- Cow milk: 90
- Cheese: 84
- Quinoa: 83
- Rice: 83
- Defatted soy flour: 81
- Fish: 76
- Beef: 74
How much protein should you eat?
This question can be answered in different ways according to your needs but I will try to make it as simple as possible for you:
- If you are cutting (trying to lose fat): It would be a good idea to keep your protein intake quite high, my personal range is 1.8-2.5 g of proteins per kilogram of bodyweight. As seen in this study keeping a high (2.4g per kilogram in this case) helped not only maintain but also build lean mass. Also as seen here the evidence shows a 1.6-2.4 g/kg range.
- If you are bulking (trying to put as much muscle mass as possible): You should not worry about losing muscle mass so you can go slightly lower on the amount of protein in your diet so you can focus on the other two macronutrients (read more here). Anyway what the evidences show is that eating more than 1.6g per kilogram of bodyweight does not give tangible advantages.
- If you just want to maintain: I would keep it simple and be always in the 1.6-2.4 range and it will work just fine, focus on the other two macronutrients and on how to do a proper carb cycling to maximise results.