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Background: Phenylketonuria (PKU), a rare, inherited metabolic condition, is treated with a strict low-phenylalanine (Phe) diet, supplemented with Phe-free protein substitute. The optimal nutritional management of a sporting individual with PKU has not been described. Therefore, guidelines for the general athlete have to be adapted. Case presentation: Three clinical scenarios of sporting patients with PKU are given, illustrating dietary adaptations to usual management and challenges to attain optimal sporting performance. Therefore, the main objectives of sports nutrition in PKU are to (1) maintain a high carbohydrate diet; (2) carefully monitor hydration status; and (3) give attention to the timing of protein substitute intake in the immediate post-exercise recovery phase. Optimal energy intake should be given prior to, during and post exercise training sessions or competition. Fortunately, a usual low-Phe diet is rich in carbohydrate, but attention is required on the types of special low-protein foods chosen. Acute exercise does not seem to influence blood Phe concentrations, but further evidence is needed. Summary: Well-treated PKU patients should be able to participate in sports activities, but this is associated with increased nutritional requirements and dietary adjustments. Conclusions: It should be the goal of all sporting patients with PKU to maintain good metabolic Phe control and attain maximal athletic performance. [ABSTRACT FROM AUTHOR]

Background: Severe intellectual disability and growth impairment have been overcome by the success of early and continuous treatment of patients with phenylketonuria (PKU). However, there are some reports of obesity, particularly in women, suggesting that this may be an important comorbidity in PKU. It is becoming evident that in addition to acceptable blood phenylalanine control, metabolic dieticians should regard weight management as part of routine clinical practice. Summary: It is important for practitioners to differentiate the 3 levels for overweight interpretation: anthropometry, body composition and frequency and severity of associated metabolic comorbidities. The main objectives of this review are to suggest proposals for the minimal standard and gold standard for the assessment of weight management in PKU. While the former aims to underline the importance of nutritional status evaluation in every specialized clinic, the second objective is important in establishing an understanding of the breadth of overweight and obesity in PKU in Europe. Key Messages: In PKU, the importance of adopting a European nutritional management strategy on weight management is highlighted in order to optimize long-term health outcomes in patients with PKU. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

The usual treatment for phenylketonuria (PKU) is a phenylalanine-restricted diet. Following this diet is challenging, and long-term adherence (and hence metabolic control) is commonly poor. Patients with PKU (usually, but not exclusively, with a relatively mild form of the disorder) who are responsive to treatment with pharmacological doses of tetrahydrobiopterin (BH4) have either lower concentrations of blood phenylalanine or improved dietary phenylalanine tolerance. The availability of a registered formulation of BH4 (sapropterin dihydrochloride, Kuvan®) has raised many practical issues and new questions in the dietary management of these patients. Initially, patients and carers must understand clearly the likely benefits (and limitations) of sapropterin therapy. A minority of patients who respond to sapropterin are able to discontinue the phenylalanine-restricted diet completely, while others are able to relax the diet to some extent. Care is required when altering the phenylalanine-restricted diet, as this may have unintended nutritional consequences and must be undertaken with caution. New clinical protocols are required for managing any dietary change while maintaining control of blood phenylalanine, ensuring adequate nutrition and preventing nutritional deficiencies, overweight or obesity. An accurate initial evaluation of pre-sapropterin phenylalanine tolerance is essential, and the desired outcome from treatment with sapropterin (e.g. reduction in blood phenylalanine or relaxation in diet) must also be understood by the patient and carers from the outset. Continuing education and support will be required thereafter, with further adjustment of diet and sapropterin dosage as a young patient grows. [ABSTRACT FROM PUBLISHER]

Summary: Background: Dietary phenylalanine restriction is the cornerstone of phenylketonuria (PKU) management. However, there are no European consensus guidelines for its optimal dietary care. Methods: Detailed information on the routine dietary management of PKU was obtained from 10 European centres using structured questionnaires. Each centre was represented by one dietitian/nutritionist or physician (European Nutritionist Expert Panel). Results: All centres screened for PKU within the first 10days of life. PKU prevalence was highest in Turkey. The training, roles and responsibilities of dietitians and nutritionists varied widely; in some centres dietitians were responsible for managing the diet, while in others this was performed by a physician. There were marked differences in target blood phenylalanine concentrations, the dosages of protein substitutes, systems for allocating daily phenylalanine allowance, and the definition of foods that could be eaten without restriction (‘free foods’). Eighty percent (n =8/10) of centres encouraged breastfeeding together with protein substitute in infants with PKU. Conclusions: Important differences exist among centres across Europe in the dietary management of PKU, and in support systems designed to assist patients in managing their diets. Further studies are needed to compare different dietary treatments with the aim of identifying best practice to optimise phenylalanine control and dietary adherence. [Copyright &y& Elsevier]