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NSPKU Society Dietitian and NHD regular contributor, Suzanne Ford, explores how PKU patients might be coping in the confines of lockdown.

During the Covid pandemic, metabolic specialist dietitians have maintained regular, remote, contact with patients via emails, phone and sometimes through videos. In different ways, the resources at patients’ disposal may have changed – sporadic food access in supermarkets and difficulties in primary care getting prescription foods. But perhaps PKU patients have more time available for aquiring those much-needed skills to maintain their strict and complicated diet.

I am writing when we are six weeks into ‘Lockdown’: 45% of the population is working from home; many people are ‘furloughed’; contracts paused or stopped, so some are not working at all. On the social media pages for groups and ‘feeds’ catering for people with PKU, we can see that low-protein baking and making food from scratch are being embraced by some for the first time, or by others to an extent never before established.dietitians have maintained regular, remote, contact with patients via emails, phone and sometimes videos. In different ways, the resources at patients’ disposal may have changed – sporadic food access in supermarkets, difficulties in primary care getting prescription foods, but perhaps during the lockdown, PKU patients have more time available to learn the skills required for their specialist and complicated dietary treatment.

The only treatment (in the UK) for PKU is a complex lifelong regimen, with tighter control needed at different life stages.The diet is usually about 10g protein per day,2 and protein-containing foods are either counted or measured down to 0.3g protein per serving. The complexity of the diet has evolved over 20 to 30 years and details have only just been agreed by specialists.3

As the diet depends upon restricting the phenylalanine content of foods, it is necessary to plan, shop for ingredients, weigh foods and cook/prepare foods with great care. Baking with low-protein products and no egg takes quite some skill and not everyone acquires the ability. The time commitment needed for a low-protein diet is considerable and has been measured. Imagine making ALL of your own bread from scratch every week for your whole life! Not a special lockdown treat, but a lifelong necessity.


Peer-reviewed evidence4 shows that the time needed for PKU management is approximately 13-19 hours per week, which includes:

  • food Research and cooking from scratch/baking bread = 9 hours;
  • weighing foods = 1.75 hours;
  • protein intake note-keeping = up to 1.5 hours;
  • managing prescriptions and blood testing/posting blood tests = 1 hour;
  • in children/young people, taking protein substitutes = 5 hours.

The above relates to people who did not have impaired intellectual or executive functioning. In individuals with impaired neurocognitive functioning (a recognised side complication of undertreated PKU, well evidenced by many, including Palermo et al5), the time taken to manage the diet is longer. Further evidence shows that, in order to achieve the best health outcomes for adults self-managing their PKU, part-time working and flexible working patterns are best.6

Some aspects of lockdown have indirectly removed another source of difficulty for people with PKU. In a peer-reviewed paper2 reporting on life with PKU from  an online survey run by the NSPKU, almost half of parents and caregivers (51% [n=120/236] and 44% of adults (n=126/286)] described social exclusion because of the diet. From the theme of social isolation, respondents identified this as a source of upset, frustration, embarrassment and a major barrier to adherence and how it made them feel different from their friends and colleagues. Inability to access suitable food in restaurants, at work and related social activities was common – since lockdown began, we are eating in our own homes within families or close social groupings.

As the Government prepares to ease us out of lockdown, I hope that those who have gained new self-management skills in low-protein cooking, researching, planning and executing a complex treatment regimen, can continue. However, these questions must be asked: is 13+ hours a week on self-management sustainable lifelong in our modern world and should the NHS invest in modern treatments (available outside the UK), for rare disease patients?

Suzanne Ford

Society Dietitian for National Society for Phenylketonuria
and Specialist Dietitian, North Bristol NHS Trust

Top photo credit: Photo by Gaelle Marcel on Unsplash

References and further reading:

  1. van Spronsen F et al (2017). Key European guidelines for the diagnosis and management of patients with phenylketonuria. The Lancet Diabetes and Endocrinology. Vol 5, Issue 9, September 2017, p 743-756
  2. Evans S. Development of national consensus statements on food labelling interpretation and protein allocation in a low phenylalanine diet for PKU. Orphanet Journal of Rare Diseases (2019); 14:2
  3. Ford S, O’Driscoll M, MacDonald A. Living with Phenylketonuria: Lessons from the PKU community. Mol Genet Metab Reports. 2018; 17(August): 57-63. doi:10.1016/j.ymgmr.2018.10.002
  4. MacDonald A, Smith T, de Silva S et al. The personal burden for caregivers of children with phenylketonuria: A cross-sectional study investigating time burden and costs in the UK. Molecular Genetics and Metabolism Reports 9 (2016) 1-5
  5. Palermo L et al. Cognitive outcomes in early-treated adults with phenylketonuria (PKU): A comprehensive picture across domains. Neuropsychology. 2017; 31(3): 255-267
  6. Riva MA1, Madotto F, Turato M, Salvatici E, Indovina S, Giovannini M, Riva E, Cesana G (2017). Work activity and phenylalanine levels in a population of young adults with classic PKU. Med Lav. 2017 Apr 21; 108(2): 118-122




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