Low Protein Diet
What is protein?
Protein is one of the basic building blocks of the body and is found in every cell in our bodies. Proteins are also found in our food. Proteins are made up of amino acids.Each protein has a specific sequence and number of amino acids. Amino acids are either essential, which means they cannot be produced by the body and must be taken in the diet or non-essential which means that our bodies can make them. The essential amino acids are Leucine, Isoleucine, Valine, Threonine, Methionine, Phenylalanine, Tryptophan and Lysine. Children also require a dietary source of Histidine.
Why might the protein in the diet need to be limited?
Some of the Inherited Disorders of metabolism require a low protein diet as treatment. Limiting the protein will help to prevent the build-up of toxic substances which could damage the body.
How do I manage a low protein diet?
Being on a low protein diet can be tricky. The level of protein restriction required will vary depending on the condition being treated and will be discussed in detail with you by a dietitian.
In general high protein foods such as meat, fish, poultry, cheese and eggs need to be avoided. Foods from plant based foods (e.g. vegetables, bread, rice etc) are a less concentrated source of protein and may be included in the diet, usually as part of an exchange list. Any missing amino acids are replaced by the intake of special protein mixture or protein substitute to support healthy growth and development.
There are many special Low Protein food alternatives such as Low Protein Bread, Pizza Bases, Flour-Mix, Biscuits and Cookies, Pasta etc which are usually allowed freely and available to you on prescription. These low protein food play an important role in a low protein diet, as well as adding variety to your meals.
The dietitian involved with each person on a low protein diet will spend time checking that a low protein diet still provides safe levels of protein, as well as other essential vitamins, minerals and fatty acids. Therefore, it is normal that everyone will have different low protein diet plan.
What are exchanges?
In some low protein diets the protein amount allowed is described in terms of amino acid exchanges e.g. in PKU the diet is made up of a number of 50mg phenylalanine exchanges (i.e. the weight of food which provides 50mg of phenylalanine). A 50mg phenylalanine exchange for PKU is equivalent to approximately 1g protein. An exchange list is given by the dietitian so that the diet can be varied by swapping one food for another. For instance in PKU 30ml of cow’s milk or 20g baked beans or 10g of Weetabix all provide 50mg of phenylalanine or roughly 1g protein.
In other conditions e.g. Tyrosinaemia the amount of protein allowed is measured in terms of 1g protein exchanges (i.e. the weight of food which provides 1g of protein).
It is a good idea to spread the amino acid or protein exchanges throughout the day rather than eating them all in one go.
Why do I need to take a special protein/amino acid supplement?
In many conditions that require a low protein diet a special amino acid/protein supplement will need to be taken (e.g. Phenylalanine free protein substitute in PKU). This supplement helps the body to avoid breaking down its own body protein, which could make levels of toxic amino acids in the blood worse. Ideally the amino acid/ protein supplement should be spread throughout the day so that its effects are maximised.
How can I get the best out of following a low protein diet?
An important part of a low protein diet is the inclusion of free foods which do not count towards the overall protein total. Limiting dietary protein can lead to a poor energy intake so including the following foods can make a valuable difference to energy intake and improve the taste and appeal of following a low protein diet:
- Foods free from protein or very low in protein e.g. sugar, fat, jam, sweets etc.
- Specially manufactured low protein products e.g. bread, biscuits, pasta, all-purpose baking mixes etc
- Energy supplements e.g. glucose polymers and fat emulsions
Why is it important that I follow my low protein diet carefully?
Following a low protein diet can be difficult but compliance is vital for maintaining growth, health and well-being. The dietitian is there to support, answer questions and give practical advice and help.
The Juvela Low Protein Team are also doing our best to develop low protein recipes to make your diet as varied as possible, so that you are not missing out at mealtimes and snack time!