A varied diet consisting of the right balance of proteins will provide you with the building blocks for a fit and healthy body.
Proteins are like the bricks and mortar of the body; they are the basic raw material that makes up cells and organs. In fact, 25 per cent of the human body is made up of protein.
Vital for growth and development, strong muscles and repairing tissues, proteins are also needed to make hormones, enzymes and antibodies to protect us from disease and neurotransmitters to carry messages to and from the brain.
Large molecules of proteins are made out of tiny building blocks called amino acids. These tiny substances are also the end product that is required for absorption by the body when proteins are digested.
There are 25 known amino acids, eight of which are essential and must be obtained from food. If any one of the essential amino acids is missing, the effectiveness of the other seven is proportionately reduced.
It is recommended that around 10-15 per cent of the total calories in a person's diet come from protein.
For a slightly more accurate figure, however, allow 0.75g protein for every kilogram of your body weight.
A person who weight 10 stone (63.5kg), for example, should aim to eat 48g of protein per day. Of course, the quality of the protein also affects how much should be eaten. If the quality is low, then more may be needed and vice versa.
Excess protein is simply turned into glucose for energy, but extreme excess can contribute to kidney problems, loss of minerals from the bones and high blood pressure.
The quality of protein in your diet is as important as the quantity. For optimum nutrition, make sure you vary your intake of protein types.
High and low quality proteins
The balance of essential amino acids contained in a given food determines what type of protein it is.
Complete proteins
Complete or 'first-class' proteins provide the correct balance of amino acids and are found in animal-derived foods such as meats, poultry, seafood, eggs and cheese.
Incomplete proteins
Incomplete proteins or 'second class' proteins lack certain essential amino acids and therefore proteins from a variety of sources need to be balanced. They are found in plant-derived foods such as seeds, buts, lentils, beans and grains.
Balancing protein sources
Proteins should be consumed from a variety of sources to obtain the correct balance of all eight amino acids, for example, protein from pulses combined with grains such as Indian rice accompanied by lentil dhal is a healthy option.
Animal-based protein
Animal sources of protein are labeled 'first class' and are complete proteins, although it is worth remembering that many sources are high in undesirable saturated fats, even if the protein content itself is of very high quality.
You can limit your intake of animal proteins high in saturated fats by choosing plenty of lower-fat, animal-based proteins such as fish or cottage cheese. Organic meat is preferable, to ensure that it is free of injected hormones, antibiotics and pesticides. It is recommended that the diet should be varied with dairy, meat, fish and vegetable proteins. Meat should be eaten no more than three times a week.
Some animal proteins are of a higher quality than others. The following would provide approximately 20g of protein:
70g chicken breast
35g (small piece) cod
4 rashers lean bacon
2 eggs
80g cheddar cheese
2 cups of whole milk
Plant-based protein
The protein from plant-based sources is incomplete and requires varied sources. Plant-based protein sources are lower in fat and high in beneficial complex carbohydrates, often making them the healthier option.
Many incomplete plant proteins such as pulses, lentils, potatoes and rice are traditionally eaten in combination with other foods to make a complete protein when eaten as a meal. Vegetarians, therefore, need not worry excessively about 'combining' foods to make complete proteins. A vegetarian diet that is healthy and varied on a daily basis will provide an adequate and balanced intake of protein.
The following would provide approximately 20g of protein:
400g brown rice
275g tofu
70g pumpkin seeds
4 large potatoes
600g broccoli
Remember, a quarter of the body is made up of protein, making it an essential dietary requirement in every meal. Eat from a wide range of protein sources to obtain all eight amino acids for your diet.