On June 28th, 2018, the National Society for Phenylketonuria (NSPKU) is holding a special event that is meant to challenge Members of Parliament (MPs) across the UK. This challenge is called the PKU Diet for a Day and is meant to allow participants to understand the unique challenges of having to limit your daily protein intake to a maximum of 10 grams per day.
Phenylketonuria (PKU) is a metabolic disorder that is characterized by a decreased ability to metabolize the amino acid phenylalanine. It is inherited from a person’s parents and is caused by a genetic mutation. If left untreated, symptoms such as seizures, pale skin, musty body odor, mental disorders, behavioral changes, and intellectual disability. The presentation can vary depending on the how much of the enzyme needed for proper metabolism remains. Mothers with poorly treated PKU may give birth to children with significant health problems, such as small head size, heart defects, and low birth weight. To learn more about PKU, click here.
The disorder is not curable, but people with PKU must maintain a diet that strictly regulates phenylalanine intake in order to have healthy brain development. This typically results in a low protein diet, with no more than 10 grams permitted daily. Patients must take regular blood tests to monitor phenylalanine, and are given artificial protein substitutes, without phenylalanine.
When on the PKU diet, many common food items are off the menu. For the challenge, food items have been classified using a stoplight system, which can be found here. Foods to be avoided due to excess protein are under red; this includes items such as meat, flour, eggs, and nuts.
Items in the yellow section can be eaten, but portions must be monitored to avoid excess protein intake. This involves an “exchange” system to calculate how much protein is in a certain portion of food, which must be precisely weighed by participants. The yellow section includes certain types of cereal, some veggies (potatoes, baked beans, corn, and others), milk, and rice.
Items in the green section have little protein and can be consumed without worry. This section includes almost all fruits, other veggies (including onions, tomatoes, turnips, artichoke), and some fats and oils.
It should be noted that the NSPKU’s materials are only meant to serve as general guidance, and not as a replacement for a doctor or dietitian. The needs of each patient with PKU differ, and it’s important that a person’s diet is tailored to their condition.
The diet-for-a-day challenge is meant to give others insight into the daily life of PKU patients. Living with a restricted diet can be very challenging and isolating, since food plays such a large role in our culture. For ethical reasons, the NSKU is not asking that MPs or other participants to consume the protein substitute, low-protein prescription foods, or undergo blood tests as a PKU patient would.