The amount a child eats can vary day to day and even meal to meal. Portion sizes can help guide you but you should also consider your child’s appetite. Taller and more active children will eat larger portions than smaller and less active children. You should discuss your child’s food intake with their dietitian at a clinic appointment.

Children are usually offered 3 meals and 2 or 3 nutritious snacks a day to achieve their energy and nutrient requirements. This should prevent them grazing on food and encourage an appetite for meals.

It’s important to remember that your child’s appetite can be unpredictable and it is perfectly normal for the amount of food they eat to vary. However, if the amount they eat reduces significantly, you should contact their dietitian for advice.

Link to the NHS page.

Each food group is explained in more detail below

Allow your child to eat larger portions if they wish as these are low energy, high nutrient foods. 

Fruits and vegetables can be fresh, frozen, tinned or dried. A typical portion size would fit into the palm of your child’s hand, for example: 

• 2-6 carrot sticks 
• 3-5 strawberries 
• 1-2 tablespoons raisins 
• ¼- ½ banana 

Some fruits and vegetables will contain small amounts of phenylalanine (phe) and these will be counted as phe exchanges. 

As most carbohydrate-based foods contain protein your child will mostly rely on specially manufactured low protein foods such as low protein bread, pasta, cereal and rice. There are a wide variety of these low protein foods available, speak to your child’s dietitian for further information on these. 

Carbohydrate-based foods provide energy and variety and one portion should be offered at each meal. 

Example portion sizes: 

• 2-5 tablespoons low protein pasta (cooked) 
• ½-1 medium slice of low protein bread 
• 2-5 tablespoons of low protein rice (cooked) 

Some starchy carbohydrates will contain small amounts of phe and these will be counted as phe exchanges. 

Meat, fish and eggs contribute to a child’s protein intake, however the phe in these foods is much too high for a child with PKU

Protein is needed for growth and your child will get most of the “safe” protein they require from their protein substitute. It is very important that they take all their protein substitute as advised by their dietitian. 

A small amount of phe will also come from their phe exchanges, for example, from certain vegetables and starchy carbohydrates. These phe exchanges must be measured with scales.

The amount of protein substitute your child needs and the number of phe exchanges allowed will be advised by your child’s dietitian.

 Dairy and dairy free alternatives provide energy and add variety to your child’s diet. There are many low protein options available. You should speak to your dietitian about the best options for your child.

Offer your child a portion from this food group 3 times a day.

Example portion sizes:

• 100ml low protein milk alternatives

• 15g dairy free cheese alternative

 Oils and spreads should be eaten in small amounts. They can provide additional energy if your child is struggling to gain weight. However, these should be limited if you notice your child is becoming overweight.

Choose unsaturated varieties such as vegetable oil or olive-based/low fat spread.

Offer a drink with each meal/snack. Aiming for around 6 x 100-120ml drinks each day to provide adequate fluid. 

• Water or permitted drinks should be taken after a protein substitute. 
• Extra fluids may be required in very hot weather or if your child is particularly active. 
• Use beakers and cups instead of feeding bottles. 
• The best drink between meals and snacks is water. 
• Drinks containing permitted sweeteners should be well diluted, fresh fruit juice can also be diluted with water to reduce the sugar intake. 
• Tea, coffee or fizzy drinks are unsuitable for toddlers. 
• Always check labels for added sweetener (E951 or E962) which is not permitted as it is a source of phe. 

 These foods are high in energy and include protein free/low protein puddings, cakes and biscuits.

It is important to be careful with how much of these foods your child is eating so they still have an appetite for the other important food groups.

Confectionery, low protein chocolate alternatives and savoury snacks can be offered to children over the age of 2 years as a treat, but shouldn’t be too often.