Food acceptance and neophobia in children with phenylketonuria: a prospective controlled study.

BACKGROUND: In phenylketonuria (PKU), little is known about the effect of bitter-tasting phenylalanine-free l-amino acid exposure on taste preference development. The present prospective study aimed to determine the flavour preferences of children with PKU versus healthy control children.

METHODS: Thirty-five children with PKU and 35 age/gender-matched controls, aged 4-13 years, tasted 10 blinded puree foods in random order. They were rated using a seven-point pictorial hedonic scale (super yummy to super yucky) and ranked in preferential order. Caregivers completed a neophobia and food frequency questionnaire on behalf of their children.

RESULTS: Both PKU and control groups rated sweet foods higher than savoury, bitter and sour foods. However, control children ranked fruits as a group higher than PKU children (mean 3.7 versus 4.6; P = 0.03), whereas PKU children ranked vegetables as a group higher than controls (mean 5.6 versus 6.3; P = 0.05). Children with PKU had more neophobia and were untrusting/fearful of new foods.

CONCLUSIONS: Although there was some evidence to suggest that children with PKU aged ≥4 years prefer savoury foods (vegetables) more than control children, they did not prefer bitter-tasting foods, and so early and persistent administration of bitter-tasting l-amino acids was not associated with apparent taste imprinting. Neophobia appears to play significant part in food refusal in PKU, perhaps more so than taste preferences.