What Is A Protein Substitute?

Protein is a vital nutrient found in many foods in the diet, like eggs, fish, meat and even pasta and bread. Protein is used by the body to grow and maintain bones, muscles, blood, skin, hair and organs.

Proteins are made up of small units or building blocks called amino acids.

One of these essential amino acids is called phenylalanine (phe). If a child has PKU they don’t produce any (or very little) of an enzyme which is used to breakdown phe. 

If a child has PKU they don’t produce any (or very little) of an enzyme which is used to breakdown phe. If phe cannot be broken down, then it builds up in the blood to high levels which are harmful to the brain. For this reason, natural protein needs to be extremely limited in the diet.

Individuals with PKU still need protein in order to support their growth and development. A protein substitute provides “safe” protein, without the phe.

As well as “safe” protein, protein substitutes usually contain other nutrients such as carbohydrate, fat, vitamins and minerals.

Carbohydrates can be used by the body as a source of energy and to keep muscles and organs working. 

The main function of fat in the body is to provide energy and help form cells and tissues. Fat carries the fat-soluble vitamins A, D, E and K into the body and helps in their absorption. 

Vitamins A, B, C, D, E and K are essential nutrients that are only required in very small amounts. They have many different important functions such as keeping our eyes, skin and nervous system healthy and helping the immune system. 

Like vitamins, minerals are essential nutrients that are only required in small amounts.

Examples of minerals are calcium which is crucial for building bones and iron which is needed for healthy blood.

As the diet can be so restrictive, individuals are unable to get all the nutrients required by food alone. This is why a protein substitute is essential.