What is protein?
Protein, the most abundant nitrogen containing compound and is an extremely important macronutrient as it is present in every cell and needed for all life functions. It is also a source of energy, providing 4kcal/g.
Why do we need it?
It is used for the growth and repair of muscle tissues, transporting oxygen, hormones, immune function and helps metabolic reactions to occur by enzyme action.
How much energy does it yield?
Protein yields 4kCal/g.
How much do we need?
The amount of protein needed every day varies for everyone, based on their weight, gender, and activity level. The normal recommendation of protein is 0.8 grams for every kilogram of body weight. However, for endurance athletes, i.e. marathon runners, about 1.2 to 1.6 grams per kilogram of body weight is required, to reduce the risk of injury and to maximize results. Please note that there are many athletes and serious exercisers who consume much more protein than this. It is quite common to consume 2g per kg/bodyweight.
Some more information:
Amino acids are the building blocks of protein. During digestion, protein is broken down into smaller amino acid units. There are about 20 different naturally occurring amino acids, divided into ‘essential’ and ‘non-essential’, with these terms referring to whether the selected amino acid can be made within the body or if it must be consumed, in order to allow for protein synthesis to occur. Essential amino acids (EAA’s), of which there are 9, need to be eaten from food. Non-essential amino acids can be made by the body.
Protein can be found in many sources and is classed by whether is it High or Low Biological Value. Animal protein contains all 9 of the EAA’s and is considered High Value Protein. Vegetable sources of protein are considered Low Value Protein, as there is usually one or two of the EAA’s missing. If you are a vegetarian, you need to make sure you are getting your protein from a variety of sources, e.g. mix a grain with a pulse to compensate for missing EAA’s. This is called protein complementation.
High Biological Value proteins are primarily animal proteins such as eggs, meats, chicken, and fish. There are only a few plant sources of High Biological Value protein: quinoa, buckwheat, chia and amaranth and tofu/soyabeans. Other plant-based sources include grains, nuts, seeds and legumes such as beans and peas.