Meal Plan for Phenylketonuria (PKU) - Adult

Phenylketonuria (PKU) is a rare inherited condition in which there is a build up of the amino acid phenylalanine in the body. PKU is tested for at birth of newborns by measuring phenylalanine levels in the heel-prick blood test. High levels of phenylalanine are toxic to the brain, and will affect brain development, and the PKU sufferer will develop learning and behavioural difficulties.

For the full principles of a PKU diet see the meal plan for PKU – child.

PKU is completely treatable by diet during childhood. It was previously believed that after around the age of 20 years old, as the brain is fully developed, the individual could then explore a more varied and 'normal' diet, without being so strict. However recent research indicated that adults who go back onto a full PKU diet had improved memory, concentration and work output, than when they were eating a 'normal' diet. Therefore it's now recommended that the PKU diet is for life, although as an adult you need not be quite as strict.

Adults with PKU who were not diagnosed or treated as a child will have significant learning and behavioural problems, and will need full time care. It is important that these adults follow a full PKU diet similar to a PKU child with appropriate protein exchanges, protein substitute amounts and enough food to meet other nutritional and energy requirements. Behaviour of these adults on a PKU diet is much improved compared to when they eat protein foods.

The following meal plan is a suitable healthy diet for an adult with treated PKU. It is a guide to the sort of foods which should be eaten, and can be more relaxed than they were following whilst a child. Consult your doctor before commencing such a regimen, as it may be required for blood levels of phenylalanine to be monitored regularly. Follow the principles outlined here and your doctor or dietitian will advise on a suitable protein substitute. Adjust 50mg protein exchanges according to your phenylalanine levels. Ensure that you eat sufficient food for any physical activities you do, so take advantage of specially formulated low protein products, like bread, flour, biscuits and pasta. Use the plan to give you an idea of what are healthy nutritious foods to include for a balanced diet and for structure, but don't forget to vary your food choices and to drink plenty of water through the day.