by Linda A. Gleason, MS, RD
© University of Wisconsin-Madison 2000
for use with Know to Grow Session B1
When my parents talk about me,
they often talk about phe.
When my doctor talks about phe,
he’s often talking about me.
When my dietitian talks about me,
she talks a lot about phe.
It started at the beginning,
well almost the beginning of me.
A week after I was born my parents got a phone call.
They were told that my phe was high.
Every baby gets a blood test
soon after they are born.
My test showed that I had too much phe in me, actually too much phe in my blood.
My parents had my blood checked again
and sure enough-
there was still too much phe in me.
It meant I had a serious disorder called phenylketonuria.
PKU for short.
Too much phe for too long would mean that my brain would not work right.
I would not learn to do many things that they had hoped I would be able to do.
Babies with PKU who were not treated, grew to be mentally retarded.
But my parents were very hopeful ---
there was a treatment.
The treatment has a lot to do with
my body was not using phe in the usual way.
Phenylalanine is one of those amino acids found in the protein in food.
Phenylalanine is what I call “phe” for short.
When we eat protein
our bodies break it apart into small pieces,
called amino acids.
Our bodies do this so it can use the amino acids from food protein to make muscles and new proteins.
Building a new body protein from amino acids from food proteins.
In other words, our bodies break up food proteins for the parts.
Everyone needs body protein to keep them
Because phe is part of protein, foods that have lots of protein have lots of phe.
In someone who doesn’t have PKU,
it’s OK if they get lots of phe.
1st phe goes to 2nd phe
make body proteins gets changed
for growing to
So all of the phe gets used up.
this is how my body uses protein.
My body can use phe to build body proteins.
1st phe goes to
phe cannot be changed to tyrosine
make body proteins
for growing and working
Here’s the difference.
My body cannot change any extra phe to tyrosine.
If I eat too much protein from food, any extra phe builds up in the blood and is harmful to me.
The extra phe is especially harmful to my brain.
The tricky part about all this is that
I still need some
phe for me.
I also need all the other parts of protein
so I can make body proteins
including my muscles.
My parents learned about the treatment for PKU when I was a baby and I still follow it today.
But I don’t get too much phe in my diet to make my level too high.
I call it my milk but it’s not from a cow.
I drink it every day!
It has lots of protein,
but no phe, and that’s perfect for me.
All of the phe I need for me comes from foods that are low in protein.
Fruits, vegetables, cereals, crackers, and special low protein foods are low in protein.
They are “yes” foods.
“Yes” foods have a small amount of phe.
I eat “yes” foods in the right amounts so I get just the right amount of phe for me.
That means I weigh or measure out the
“yes” foods I eat.
Even too many “yes” foods give
phe to me.
I never eat meat, fish, chicken, eggs, cheese, nuts or milk.
They have way too much phe for me.
Now phe and me get along famously.