Phenylketonuria (PKU) is characterized by phenylalanine (Phe) accumulation to toxic levels due to the low activity of phenylalanine-hydroxylase. PKU patients must follow a Phe-restricted diet, which may put them in risk of nutritional disturbances. Therefore, we aimed to characterize body composition parameters and nutritional status in Brazilian PKU patients also considering their metabolic control.

Twenty-seven treated PKU patients older than 5 years, and 27 age- and gender-matched controls, were analyzed for anthropometric features and body composition by bioelectrical impedance (BIA). Patients' metabolic control was assessed by historical Phe levels.

There was no effect of PKU type, time of diagnosis, or metabolic control for any analyzed parameter. About 75% of patients and controls were eutrophic, according to their BMI values. There were no difference between groups regarding body composition and other BIA-derived parameters.

Brazilian PKU patients do not show differences in body composition and nutritional status in comparison with controls, regardless metabolic control. Although similar to controls, PKU patients may be in risk of disturbed nutritional and metabolic markers as seen for the general population.