What are proteins?
Proteins, just like carbohydrates and fats, are a source of energy for the body. In fact, around 20% of the body is made up of proteins!
Protein is needed to build, maintain and repair all the tissues of the body. These tissues make up our muscles and organs. That means every organ and every muscle in our body is made up of protein, even our skin, hair and nails.
Proteins are made up of amino acids which are joined together in long chains. The main elements found in amino acids are carbon, hydrogen, oxygen and nitrogen. If you look at amino acids under a microscope, they look a bit like tangled strings or party balloons.
There are many different types of amino acids but 22 are really important for our health. From these 22, the body can make 13 of them all by itself, but the other 9 it must get from the food we eat. These 9 amino acids the body can’t make are absolutely essential for the body to function properly, which is why they are called essential amino acids.
Types of protein
Protein is found in many foods, some of the most common are meat, fish, eggs, nuts, seeds, legumes, tofu and vegetables.
The food we eat is classified into complete protein and incomplete protein.
Complete protein are foods that contain all the essential amino acids our bodies need. Meat, fish, seafood, eggs and soy contain complete protein.
Incomplete protein is found in nuts, grains, fruits and vegetables and do not contain all the essential amino acids. We need to eat a variety of these to get what we need.
How do our bodies use proteins?
The foods we eat have to be broken down first before we can use them. They need to be made small enough to enter our cells and travel through the body.
When we eat foods that contain protein, the stomach and intestines break down the proteins into really small pieces, into amino acids. The body then sends these amino acids to different parts of the body to build proteins of the body, like the muscles, bones, blood, organs, hair, nails and skin.
- The word protein comes from the Greek word proteios which means primary or in the lead.
- After water, protein is the most abundant substance in the body.
- Hair, nails and the outer layer of the skin are made of a protein called keratin.
- Eating too much protein can be stressful for the liver and kidneys, forcing them to work extra hard, it can also cause weight gain.
- Some proteins like gluten can cause allergies. Gluten is a wheat protein found in many grains.
- Some people eat insects as a source of protein, they contain high levels of protein.
- Collagen is a protein needed for our skin, cartilage and tendons.
- Proteins are needed to make antibodies which fight off diseases.
- Haemoglobin is a protein found in the blood, it helps carry oxygen in red blood cells.
- Some proteins break up food in our digestive system.