We volunteered ourselves to undertake the ‘7 Day 7 Exchange Dietitian Challenge’ as part of International PKU Day which was on June 28th and also to learn about what our patients do on a daily basis. Click here to find out more about the challange.

We work with adults with PKU, therefore our views and thoughts about the diet challenge is tailored towards adults following the PKU diet. Infants, children and pre conception/ pregnant ladies have to follow the diet much more strictly than adults.

Sarah’s Thoughts

So the challenge is over. It has been a fun, tiring, hungry, fascinating, eye opening week.

I was genuinely worried about doing the PKU 7 day 7 exchange challenge as I thought I would fail. I love my food, am always hungry and I didn’t want to let our patients down; the people who do this day in, day out. Despite this fear, I was also really keen to see what it was like to actually “be on diet”, so the advice I was giving came from experience and not just from theory.

It was hard but not as hard as I anticipated. The support from other dietitians, my family and patients has really helped.

The Highs

  • Taking the protein substitute. On day 1 it took ages. On day 7 I could neck it in less than 10 seconds. It actually tasted better than I thought it would. I only tried the Lophlex and Lophlex powder as couldn’t bring myself to try tablets and the pudding version.
  • Eating out with Louise. Although we knew we went over our exchanges slightly, it was still possible and we had a great time.
  • Being absolutely fine with exercise. In fact I had lots of energy. This may have been due to eating more carbohydrates than normal, which has taught me a bit about my normal diet.
  • My tummy. This may be a bit of too much information but my tummy habits have been so healthy; the best in a long time. I won’t delve much further into that one!

The Lows

  • The hunger. I won’t lie. Breakfast and mid afternoon were hard going. I was so hungry coming home from work and being faced with a Lophlex and some fruit to tide me over until tea got harder as the week went on.
  • The tiredness. I have been so tired all week and very apathetic. I’m not sure if this is lack of natural protein, less calories or being phenylalanine deficient! My husband said I was “out of it” and “not myself”. I struggled to keep my cool with my daughter if she played up and was quite tearful a couple of times.
  • Messing up. I put milk in my tea without thinking and wasted an exchange. I licked the yoghurt lid from my daughter’s pudding. I licked the knife with Marmite on it. I found my hand in the almond jar a couple of times only stopping when I realised. Habits are very hard to break.

What Low Protein Foods I Used

Patients comes to us saying they have tonnes of low protein foods in the cupboard, the garage, the loft and I used to think why? Don’t you eat it? The answer is no. I didn’t and have tonnes of stuff left. I used:

  • Sno Pro low protein milk   – I opened 5 but only used a bit in my tea
  • Loprofin slice loaf – 1/2 a packet
  • Juvela low protein cookies – whole box
  • Juvela pizza base – 1
  • Loprofin penne pasta – 1/3 box
  • Loprofin herb crackers – 2 boxes

I’m not really a dietitian who does a look of baking and cooking. I love my food but unlike Louise, it’s not something I do a lot of so the ready to-use foods were used a lot more!

What Did I Use for Exchanges?

As I am used to eating natural protein and am used to the taste and texture, I wanted to use these foods for my exchanges. For someone on a strict PKU diet since childhood, they may not want to do this due to their tastes. Someone returning to diet, after a break may find the foods I picked useful. I used the following foods for exchanges:

  • Basmati Rice (uncooked) – 35g = 3 exchanges
  • Genius Gluten free bread – 1 slice = 1 exchange                                           IMG_3776
  • Greek Yoghurt – 44g – 2 exchanges
  • Amoy Rice Noodles – 1 pack – 2 exchanges
  • Cheese – 13g = 3 exchanges
  • Sweetcorn – 35g – 1 exchange
  • Garabaldi Biscuits – 1 = 1 exchange
  • Chocolate – 15g = 1 exchange
  • Heinz Carrot and Coriander Soup – 1/2 tin = 1 exchange
  • Semi-skimmed milk – 30ml = 1 exchange
  • Vegetable Fingers – 1 = 1 exchange

I am a creature of habit. I get into a routine and stick to it. Breakfast was always toast and fruit, as I’m not a cereal person. I don’t really eat crisps so it was hard to add them in. Therefore, I thought my exchange list wasn’t that big.

Meal out (estimated!):

  • Fries 1.5ex
  • Croutons 1ex
  • Sweetcorn fritters 1 ex each

7 day 7 exchange meal out

What Have I Learnt?

  • The PKU Diet if followed strictly, with no cheating, is a daily challenge for anyone and I have even more admiration for what our patients achieve on a daily basis.
  • Habits are hard to break. It is so easy to cheat and lick a knife or yoghurt lid or not bother to weigh things out. I feel I understand my patients more when they say they just guess or when a diet history reveals extra protein hidden away. This must be tricky when coming back to diet but overtime this gets easier, with practice.
  • Support is vital. Family, friends who will help you with cooking and plan meals. I’m lucky I have a husband who is the chef so our meals were easily adapted. He just added chicken or prawns to curry or stir fry for example. Without this, it would have been a lot harder.
  • Planning is so important. You can’t just visit a friend or even go to work without your meals planned and lots of food. It’s worth writing your weekly meal plan out or at least having it in your head. I did and this made food shopping easier. I had to prepare my work lunches the night before. If I hadn’t I knew I would end up eating something with more protein in it.
  • You need to eat regularly to keep full as I was hungry a lot. You need to have a supply of low protein foods, especially if you don’t have many exchanges to play with. I was always munching on fruit or low protein crackers.
  • It is very easy to overeat. I was so hungry I polished off a box of low protein cookies in 2 nights. If this continued I can see how it is easy to gain weight.
  • Eating out is hard work unless you are going to bring scales with you. Not all places have low protein options. The vegan menu is full of lentils and chickpeas. You have to guess what exchanges you are having and it is more than likely you will overdo it.
  • You can exercise and perform well with PKU. Planning, regular meals, snacks and taking your protein substitute play vital roles in this.

Lophlex after exercise 7 day 7 exchange


Louise’s Experience

When we were first asked to do this challenged I jumped at the chance. I advise people on how to follow a PKU diet every day at work, but I have never followed it my self. It is not a diet you chose to be on if you do not have PKU as it is very expensive in terms of the protein substitutes and prescribed low protein foods. But for those with PKU it protects their brains in infancy and improves their quality of life in adults. I wanted to experience the diet first hand so I had a ‘little experience’ of what I am talking about!

The Highs

  • I did it! I managed to get through the week and mainly managed to sick to 7 ex per day (well apart from going out to dinner and I went up to 9.5 ex that day and I had 7.5 ex on Thursday when I had 2.5 ex of mashed potato!).
  • I nearly managed all the protein substitutes (my protein source without the phenylalanine) apart from only managing 1/2 my dose of tablets on Wednesday and the very last one of day 7 when I caved and had peanut butter on toast and milk (instead of my PS) after I came home at 10pm after my orchestra concert!
  • Finding low protein foods in the shop that I could eat! – Rice noodles, vegan cheese, cracker breadsLow protein Laksa 7 day 7 exchange
  • Cooking the Simon Rimmer Low Protein Laksa which was lovely. I made it for the rest of the family and they added prawns to theirs!
  • The great support from our patients, other dietitians and family.

The Lows

  • The restriction. I do not have any food allergies or intolerances so I have never had to be careful about what I eat. The first 2 days I kept forgetting and ate a biscuit when we were out and tipped cows milk into my tea… wasted exchanges that day!
  • Self control. I had to have strong will power to stick to the diet, although  it was easier for us as we were only doing a week and we had the end in our sights. I would imagine it would be 10 times harder knowing I had to be on in indefinitely if I was someone with PKU returning to the diet.
  • I realised how much I pick at my children food when they don’t eat it or when I am cooking it to check it tastes nice, so I had to stop my self doing that.
  • The hunger. Waking up in the mornings feeling really hungry (and even a bit sick one morning). This could have been because natural protein keeps you fuller for longer or maybe I was becoming a little phenylalanine deficient as only eating 7 ex per day and my body can breakdown phe into tyrosine efficiently unlike people with PKU.

Low Protein Foods

For the diet to work, you have to rely heavily on low protein foods that can only be obtained on prescription. I didn’t use as much prescrible low protein foods as I thought I would, but still a sizable list. This is what I used over the week

  • Fate All Purpose Low Protein Mix 500g- 1.5 bags (I made a loaf in the bread machine with 1 x 500g packet, pizza base with pancakes with the other 1/2 packet)
  • Fate Low Protein Plain Cake Mix 250g – 1 bag (I made a carrot and pineapple cake)Fate bread 7 day 7 exchange
  • Promin Breakfast Bars x 3
  • Promin Sausage Mix x 1 packet
  • Sno Pro 200mls x 3
  • Loprofin Cereal Loops – 1/4 packet
  • Loprofin Pasta – 1 portion
  • Loprofin Sliced Bread – 1/2 packet
  • Juvela Pizza base – x2
  • Juvela Choc Chip Cookies – whole pack!

Specific low protein foods (can be used without counting) bought from shops

  • Violife Cheese Block – used 3/47 day 7 exchange
  • Violife Cheese Spread – used 1/4
  • Rice milk
  • Koko milk (coconut milk)

Exchange foods

If you are on a totally phenylalanine free diet then you will become deficient in phenylalanine, so our challenge was to have  7 exchanges worth of phenylalanine per day. Depending on the severity of PKU, this could be as low as 3 ex or as high as 30 exchanges. 1 exchange = 50mg of phenylalanine (1 g protein). These are the foods I used during the week.

  • Frozen Potato waffles 1= 1ex
  • Malted milk biscuit (by mistake!) 1=0.5 ex
  • Chocolate digestive biscuit (at orchestra rehersal break!) 1 = 1ex
  • Quavers 1 packet = 0.5ex
  • Roast potatoes 55g=1ex (I used 1.5 ex in my portion)
  • Promin sausage mix 1 packet = 0.5ex
  • Mini ice cream on a stick 1 = 1ex
  • Cereal loops 24g for 2ex
  • weighing cereal 7 day 7 exchangeGranola 20g = 2ex
  • Ryvita Wholegrain Cracker bread 2 = 1ex
  • Heinz carrot and coriander soup 1/2 can = 1ex
  • Sweetcorn 35g = 1ex
  • Cereal bar 1 = 1ex
  • Green Thai Vegetable Bake from Tesco 1 = 3ex
  • Milk in tea 30mls = 1ex
  • Cheese triangle (Laughing cow) 1 = 2ex
  • Philadelphia Cream Cheese 35g pot = 2.5ex
  • Vegetable fingers 2 = 2ex
  • Mashed potato 200g = 2.5 ex
  • Ribbon Rice Noodles (Amoy) 150g = 1ex
  • Dark choc 3 square ~ 1ex

Meal out (estimated!):

  • Fries 1.5ex
  • Croutons 1ex
  • Sweetcorn fritters 1 ex each

What Have I Learnt?

  • For the diet to work you need to be disciplined, organised and have the information you need at your finger tips. This is hard to do and I can see why a lot of people struggle.
  • For a quick way to check suitable foods, I down loaded the NSPKU dietary booklet on my iphone and then adding it to my ibooks so I could look at it when ever I needed to check something (I am sure similar things can be done on Android phones… let me know!).
  • It is worth doing some cooking and baking with the low protein products. I really enjoyed my cake, pancakes and pizza that I made with the Fate mix. Making the fresh bread in the bread machine was worth it as the texture and taste was much better. Making the effort to bake and cook in bulk and freeze so you can have fresh prepared meals / bread / cakes when you need them is worth it.

LP cake 7 day 7 exchange

  • Having enough low protein foods on prescription, especially staples like flour, bread, crackers and pasta is essential. Slipping on to normal bread and pasta will soon eat up the exchanges.
  • If you have a family or partner to cater for as well, then try and plan meals together so you are not cooking too many different things. For example making pizza (have a LP base and normal base and choose your own toppings), Pasta meal (start with the same vegetable sauce, take portion out for yourself and then add meat, fish or cheese for the rest of the family and cook LP and normal pasta respectively). Vegetable stir fry with rice noodles (counted as exchanges), add protein source for rest of family.

LP sunday dinner 7 day 7 exchange

  • Having some one to support you. Sarah and I were lucky to be doing it together so we could encourage each other and discuss what we were eating. Having a friend to talk to who also has PKU will help. Going to your PKU clinic or attending PKU events is a great way to meet new people. The world is now a smaller place and you can talk to people from all over the world on social media!
  • Trying out different protein substitutes to see what suites you the best is essential as you have to take them at least 3 times a day, everyday. The ready to drink liquid pouches are the most convenient, but I found the taste of the powders ones slightly better. I could not manage the tablets at all!!

Protein substitute 7 day 7 exchange

In conclusion

It has been a really interesting week for me, learning how the diet works practically. It has given me much more insight into the diet and hopefully will make me a better Dietitian.