Acceptability and Tolerance of a Ready-to-use Protein Substitute in Tablet Form for the Dietary Management of Phenylketonuria

Intervention is a Phenylalanine-free protein substitute in tablet form. Subjects who currently take a concentrated second stage phenylalanine-free protein substitute will be recruited. Subjects will take the study product for 7 days and daily questionnaires will be completed. Subjects will replace some or all of their usual protein substitute with the new product. The amount of study product prescribed will be calculated to provide the same amount of protein as their usual protein substitute. Daily acceptability and tolerance questionnaires will record information on ease of preparation and administration; how it is taken; and any problems or gastrointestinal effects. Additional questions at the beginning and end of the study will record information on taste, appearance, smell, presentation and packaging of the product. Routine weekly finger prick blood spots will be collected and analysed for phenylalanine and tyrosine as usual.