How Much Should My Child Eat?

Children with PKU should eat roughly the same amounts as a child of the same age without PKU. Throughout their childhood, many things will change in your child’s life including their appetite. 

Even in children of the same age, there can be a big difference in their food intake; 

• Smaller children will generally need less food than taller children. 
• Less active children will generally need less food than more active children. 

If the amount your child eat reduces significantly, or you are worried about your child’s weight, contact their dietitian for advice. 

When a child has PKU, their diet will have extra considerations, for example some foods; 

• will need to be avoided entirely such as meat and fish. 
• can only be eaten in measured quantities (counting grams of protein), these include bread and cereal. 
• must be swapped for specially manufactured low protein alternatives, such as milk and pasta. 

Your child’s specialist metabolic team will continue to see your child regularly. You can use these appointments as an opportunity to ask any questions you might have about your child’s individual diet. 

This guide is for the general population and not for people who require a low protein diet for treatment of PKU. However, with a few adaptions, the Australian Guide to Healthy Eating, can still help to guide a child with PKU. 

Below is an outline of the Australian Guide to Healthy Eating’s 5 food groups, put into context for the child with PKU.

Children need to eat a variety of vegetables daily, including different colours helps to achieve a broad range. Offer vegetables at most meals, including lunch and dinner, ideally offering at least 5 different types over the day.

Legumes and beans are usually too high in protein for the low protein diet for PKU, and therefore are not to be eaten.

Some supermarket breads, cereals, pasta, and rice may be appropriate in very small amounts, but their protein content needs to be counted as part of your child’s total protein allowance. Using a variety of the lowest protein options is important as these are generally needed to satisfy your child’s hunger.

If foods, such as bread and cereal, contains protein, the amount consumed needs to be limited and your child may lack much-needed calories. These foods make up at least 1/3 of the plate and are recommended at each (most) meal, and some snacks.

Like the “lean meat” food group above, the protein substitute your child consumes at each meal is a replacement for these foods, and should be taken at regular times over the day and in quantities as advised by your dietitian.

There are several low protein dairy alternatives that may be included in the PKU diet. These include some low protein, non-dairy “cheeses”, non-dairy “yoghurts”, and non-dairy “milks”. Labels need to be carefully read and their protein content counted as required.  Incorporating these options into the diet can greatly help to increase overall variety.

Offer fruit approx. 3 times per day. Young children will often not eat a whole piece of fruit at one sitting so offering small amounts at regular times over the day helps to increase overall intake. It is recommended for children to eat the equivalent of at least 2 pieces of fruit per day, and more if hungry.