Breaking Barriers: Stakeholder Insights into Physical Activity, Exercise, and Dietary Behaviours Among Individuals with Phenylketonuria (PKU)

<b>Background/Objectives:</b> In Phenylketonuria (PKU), engaging in regular physical activity and exercise (PA/E) is important for physical and psychological health, but additional considerations may be required to facilitate uptake and performance as well as to optimise metabolic control. The aim of this study, therefore, was to investigate the stakeholder perspectives on the barriers, facilitators, and solutions to completing PA/E, sport, and nutrition in PKU. <b>Methods</b>: In total, 7 in-person and 6 online semi-structured focus groups (FGs) were conducted with individuals with PKU (<i>n</i> = 31), caregivers (<i>n</i> = 13), clinicians (<i>n</i> = 17), and medical industry professionals (<i>n</i> = 14) in PKU (<i>n</i> = 75 total participants). Three main questions about the barriers, facilitators, and solutions to performing PA/E with PKU were explored. Identified themes were mapped onto the capability, opportunity, motivation, and behaviour (COM-B) model of behaviour change with anonymous quotes from relevant stakeholders used to illustrate the findings. <b>Results</b>: Five common themes were identified. Most notably, individuals with PKU and their caregivers stated fatigue, poor recovery, low energy, and fear around the impact of exercise on blood phenylalanine (Phe) control were barriers to PA/E. Individuals with PKU were aware of the potential benefits of exercise, stating PA/E impacted positively on their mental well-being, daily functioning, and happiness and improved their self-confidence and long-term health. Identified solutions to PA/E participation included greater knowledge in regard to the impact of PA/E on Phe levels, improvements in advice on amount and supplementation with protein substitutes, tailored PKU nutritional advice, more awareness of PA/E within and outside the PKU community, specific PKU guidelines for PA/E, more scientific research, and PA/E events. Misalignment was evident, such that individuals with PKU reported additional barriers to PA/E, whereas other key stakeholder groups perceived the same barriers as the general public. <b>Conclusions</b>: There seems to be a misalignment between individuals with PKU, caregivers, clinicians, and industry professionals regarding PA/E, sport, and nutrition. Individuals with PKU and caregivers reported additional barriers to undertaking PA/E, sport, and nutrition compared to the general public. This suggests that further education and collaboration is needed through stakeholders to better understand how such barriers could be overcome in respect of PA/E, sport, and nutrition in individuals with PKU.