Supplementary Material for: Everyday Life, Dietary Practices, and Health Conditions of Adult PKU Patients: A Multicenter, Cross-Sectional Study

<b><i>Background:</i></b> Only few data on dietary management of adult phenylketonuria (PKU) patients are published. <b><i>Objectives:</i></b> This study aimed to assess living situation, dietary practices, and health conditions of early-treated adult PKU patients. <b><i>Methods:</i></b> A total of 183 early-treated PKU patients ≥18 years from 8 German metabolic centers received access to an online survey, containing 91 questions on sociodemographic data, dietary habits, and health conditions. <b><i>Results:</i></b> 144/183 patients (66% females) completed the questionnaire. Compared with German population, the proportion of single-person households was higher (22 vs. 47%), the rate of childbirth was lower (1.34 vs. 0.4%), but educational and professional status did not differ. 82% of the patients adhered to a low-protein diet, 45% consumed modified low-protein food almost daily, and 84% took amino acid mixtures regularly. 48% of the patients never interrupted diet, and 14% stopped diet permanently. 69% of the patients reported to feel better with diet, and 91% considered their quality of life at least as good. The prevalence of depressive symptoms was high (29%) and correlated significantly to phenylalanine blood concentrations (<i>p</i> = 0.046). However, depressive symptoms were only mild in the majority of patients. <b><i>Conclusion:</i></b> This group of early-treated adult German PKU patients is socially well integrated, reveals a surprisingly high adherence to diet and amino acid intake, and considers the restrictions of diet to their daily life as low.