Phenylketonuria – Low Protein for a Week – My Challenge

Phenylketonuria – Low Protein for a Week – My Challenge

I’m a Dietitian as many of you may know. I work in quite a specialist area called Inherited Metabolic Disorders which are basically genetic conditions where a patient cannot process a specific component of food.One condition we look after is called Phenylketonuria or PKU.

This is where a person cannot break down one of the amino acids found in protein – phenylalanine. Think of protein looking like lots of beads on a chain. Each bead is a different amino acid. Remember when your 5 day old baby had their heel pricked and you watched in horror? They were screening for PKU. The only treatment currently in the UK, if diagnosed. is diet. If not followed as advised, a baby’s brain and development can be severely affected. A massive shock for any new parent and lots of support is always needed.

Diet is a low protein diet. Protein is everywhere. Places you never thought. Meat, fish, eggs, nuts, beans and dairy are the obvious choices and must be avoided. However, pasta, rice, bread, cereals and even vegetarian products are still very high. It is found in the sweetener aspartame, so many diet drinks and chewing gums have to be avoided. So what do people do? They have special drinks with all the essential amino acids, except phenylalanine and their vitamins and minerals. This provides their protein. They have special low protein foods on prescription; bread, pasta, rice, cereals, biscuits, flour, milks and meat alternatives.They eat naturally low protein foods such as fruit and vegetables, sugars and fats and oils. Depending on their severity they may have some medium protein foods in weighed amounts; rice, cereals, potato and snack foods like crisps or cereal bars.


Low protein shop

In my role I look after adults. Some are still very strict with diet, some are off diet and some are in between. The brain has fully developed by adulthood and people used to be taken off diet but now diet for life is recommended. It is a very strict regime to follow and is very challenging, especially for anyone going back to diet after a long break. Imagine going out to eat low protein. What would you have in a pub? Veggie options have cheese – not great. Most foods are all meaty. Imagine explaining your diet to others? If you were going to a wedding or party. A lot of planning, organisation and support is needed.

It is International PKU day on 28th June and my work colleague and I are following the PKU diet for a week; 7 days and 7 grams of protein a day. That’s one egg in total per day if you want an equivalent. Hard stuff!

It will be really interesting to see what our patients do on a daily basis. How they eat out, cook different meals to other family members and keep themselves full.

Check back next week to see how I got on.



(Visited 71 times, 1 visits today)


  1. June 22, 2015 / 4:32 am

    Good luck and good for you. Sounds rough! Ive just started 3 weeks of no grain, sugar or dairy today. Will probably be deep into sugar/carb withdrawl grumpiness by tomorrow.

    • June 22, 2015 / 6:05 am

      Thanks lots! I think you are insane also. Good luck and let us know how you get on! I'd miss my yoghurt tonnes! xx

  2. June 22, 2015 / 5:59 am

    This is really interesting – especially with the low carb / high protein diet trends going on. If never really thought about how restrictive the PKU diet would be before. I'll be interested to hear how you get on and if it changes the way you advise patients.

    • June 22, 2015 / 6:05 am

      Thanks Morna! I know! It is so hard. xx

  3. June 22, 2015 / 12:57 pm

    My dad's wife fosters, and one of her boys had PKU so I have heard about it before. Protein is something I definitely don't eat enough of so maybe I'd be pretty good at cutting it out?!

    • June 22, 2015 / 12:58 pm

      Oops, meant to say …



  4. June 22, 2015 / 8:43 pm

    Interesting stuff. I'd never even heard of it, but of course I remember the heel prick my sons had. It must be very difficult to live with such a disorder and I admire you for doing what you're doing. Good for you. xx

    • June 24, 2015 / 8:28 pm

      Thanks Morgan, kind of you to say xx

  5. June 23, 2015 / 8:57 am

    Wow! I'm always trying to get more protein in my diet and that of my two daughters. Living with any kind of specialist diet sounds really hard – trips out and special occasions must be fraught with difficulties. I feel for anyone with conditions like this – even more so when they are parenting a child with specialist requirements. Good luck with your week. I've followed you on FB by the way! #BloggingToJogging

    • June 24, 2015 / 8:29 pm

      It is very tricky for them but they do adapt and just live with it! Thanks lots for the comment and follow x

  6. June 23, 2015 / 7:05 pm

    What a really interesting post and lovely to find out more about what you do! Huge fan of pastrami for my protein and steak… unfortunately not a lot of that at the moment due to the TFR diet but will be stocking up when eating again. Fab post! #WeightLossWednesday Sim x

    • June 24, 2015 / 8:30 pm

      Ah no steak and pastrami! lol. You have done so well on your diet though!!! xx

  7. June 24, 2015 / 6:13 am

    It´s always good to know what your patients go through so you can be more supportive of their condition. I think its a great thing you are doing. Good luck, I dont think I could do that diet at all!

    • June 24, 2015 / 8:30 pm

      Thanks so much! I didn't think I could do it but not doing so bad x

  8. June 24, 2015 / 6:14 am

    oh, over from #bestandworst

    • June 24, 2015 / 8:30 pm

      hehe thanks! x

  9. June 24, 2015 / 6:36 am

    Good luck with this Sarah. I think it's great that you're getting hands on and experiencing what your patients go through. #bestandworst

    • June 24, 2015 / 8:30 pm

      Thanks Emily! I ate enough at the weekend to keep me stocked up x

  10. June 24, 2015 / 8:55 am

    I read a few articles when I saw PKU mentioned by the health visitor during my son's heel prick test. And I find it interesting to learn more about. It is not a condition I have come across before. Good luck with the challenge #bestandworst

    • June 24, 2015 / 8:30 pm

      Thanks and glad you have bit of knowledge x

  11. June 24, 2015 / 9:14 am

    Good luck with this hun,I'm a very naughty eater and have a sweet tooth so always find a restrictive diet in any shape or form hard work x #bestandworst

    • June 24, 2015 / 8:31 pm

      Lol it has been tricky but not long left!! x

  12. June 24, 2015 / 10:18 am

    Good luck! I haven't heard of this before, really interesting. So grateful that I can eat what I like – within reason! #bestandworst

    • June 24, 2015 / 8:31 pm

      Thanks lots and glad to pass on some info x

  13. June 24, 2015 / 12:41 pm

    sounds very difficult to stick to. I'll be curious to hear how you guys make out

    • June 24, 2015 / 8:31 pm

      Thanks Jeremy! x

    • June 24, 2015 / 8:32 pm

      I hope so! Patients are glad we are doing it x

  14. June 24, 2015 / 5:16 pm

    Wow! This sounds like it'll be tough going but am so interested in knowing how it goes! Hope to see more updates on this. #bestandworst

    • June 24, 2015 / 8:32 pm

      Thanks Martyn will keep you posted! x

  15. June 24, 2015 / 7:00 pm

    I wouldn't even know where to start. I have eczema and as I have got older I have been able to re-introduce dairy and red meat back in to my diet in moderation. H has a little bit of eczema and trying to plan his meals to cut down on dairy is proving difficult. How my Mum coped all those years ago with very few other choices amazes me. Best of luck! #bestandworst

    • June 24, 2015 / 8:33 pm

      Cutting out dairy is so hard – I would struggle! Your Mum must have done a fab job! Thanks so much xx

  16. June 24, 2015 / 8:36 pm

    Eeek! I think it's great that you're testing it out for a real experience that you can relay to your patients.


    • June 24, 2015 / 8:46 pm

      Thanks Helen! I hope they like reading about it!! x

  17. June 25, 2015 / 12:59 pm

    This was such an interesting read because I read about this when my daughter had her heel prick test because my daughters came back positive for Congenital Hypothyroidism and although she didnt have pku I had never given that much thought to the heel prick test before until they found something with hers. I feel so lucky that she just has to have a tiny pill each day because it seems so much easier than what you just described in terms of being really strict with diet -plus my daughter really really likes to eat. But without her pill, like PKU she would be severely brain damaged and have stunted growth without it. More should be done to raise awareness about the heel prick test as many parents don't even know what is being tested for. I know I didn't and got the shock of my life when I got the phone call from the hospital. Good for you for doing this and putting yourself in the people with PKU shoes for a week.

    • June 25, 2015 / 7:33 pm

      Thanks Janine. Oh that is so interesting but must have been so scary for you! Thank goodness for the heel prick test. You are right more awareness is needed as most people don't know what the tests are for xxx

  18. June 25, 2015 / 3:01 pm

    Gosh that must be so hard to live with, both as a parent of a child with PKU and actually having it. Great that you are putting yourself in their shoes and eating what they eat, cant be easy, hope it's going well!! Xx

    • June 25, 2015 / 7:33 pm

      It is very hard I can imagine! Thanks Caroline it's going ok so far xx

  19. June 25, 2015 / 7:08 pm

    Wow, it must be so hard to totally cut out such an important macronutrient from the diet. It's admirable that you are putting yourself through it as an experience. Good luck to you! I look forward to reading how you get on! 🙂 x #BestAndWorst

    • June 25, 2015 / 7:33 pm

      Thanks Michelle! I will put an update up next week x

  20. June 25, 2015 / 9:31 pm

    Oh wow – this is such a good thing to do – and will totally give you an insightful understanding of PKU. Be very interested to see how you get on (and what you can eat)! Good luck! #bestandworst

  21. June 26, 2015 / 8:24 pm

    OO this is really interesting. Look forward to next week to see how it has gone! #bestandworst xx

  22. June 30, 2015 / 8:56 pm

    Gosh, what a lot of restrictions, makes me feel so lucky. Sad that there's so little available for people with PKU xx