You may have heard of protein, but do you know what it is, what it does and the best sources?

What is protein?

Protein, along with carbohydrates and fats are macronutrients. These are nutrients that our body needs in large amounts to produce energy. In addition to being essential sources of energy, macronutrients carry out a variety of functions in the body. During digestion, proteins are broken down into smaller units, called amino acids. Amino acids are the fundamental building blocks of life, and they form the structure of our organs. They can be found in every cell in our bodies and are essential for growth, development, and repair. Apart from water, protein is the most abundant compound found in the body with around 45% of it being stored in the muscles. Protein is also very important for our bone and muscle health. This becomes especially important as we age as our muscle mass and bone density naturally decrease.

Protein in our diet

Protein is made up of a combination of amino acids. In total, there are approximately 20 different amino acids that the body requires for different roles in the body. The body can make 12 of these, however, 8 of them can only be provided throughout our diet. Many different foods provide us with protein with rich sources coming from meat and fish. These animal sources of protein are called ‘complete’ sources as they contain all 20 amino acids.

Plant-based foods such as beans and vegetables are also good sources of protein. They’re called ‘incomplete’ proteins as they don’t contain all 20 amino acids. To get all the amino acids our body needs, it’s recommended we eat a variety of foods to give our bodies all 20 amino acids. The key here is to eat as many different plants as possible, these will also be a great source of fibre.

Protein and our appetite

Our body can only digest and utilise a certain amount of protein at one time, so we need to eat protein-rich foods over the day to allow our body time to absorb the nutrients effectively. Consuming protein with each meal could also have a positive effect on your appetite. As protein is a complex structure, it takes longer to digest than fats and carbohydrates, and therefore takes longer to pass through the digestive system. The positive effect of this is that it makes you feel fuller for longer and more satisfied. This is great news for people who are looking to lose weight or reduce their snacking between meals.

How much protein?

We need adequate amounts of protein from our diet to prevent illness, and it’s recommended that adults consume 0.75g of protein per kg of body weight. For an average size woman, this equates to around 45g of protein and around 55g for a man. To reach these requirements, a healthy balanced diet is recommended. 

In recent years, food manufacturers have released several products including shakes, cereals and even chocolate bars that have a higher protein content. They’re often expensive and can be high in sugars and fats so always read the labels. They can be a great, easy supplement to your diet if you’re low on protein, but if you’re able to eat whole foods like meats, fish or pulses you may not need them.