When I was younger, my Mum would used to tell the people at the restaurant that I had something wrong with me and what I could and couldn't eat. Normally they were really nice and complimentary. One restaurant just piled a load of veg on a plate for me and didn't charge for it. Also another 1 gave me a paper cup of chips… for free.
I also went to pizza hut and took one of my pizza bases with me and asked if they could do a pizza on that. I called in advance, and they were so helpful!
There are lots of options really! Always tell the restaurant though and normally they will be more than happy to help!
We usually make due when it comes to going out to eat. Most restaurants have salads, fruits and veggie plates, and of course fries. I have never been big on asking for special accommodations aside from no cheese, bacon, etc on my salads. Special accommodations don't seem necessary for me and my sisters, because we have no problem with making due. However, everyone has to find what works best for them, and for some people having restaurants accommodate them is the best way to go.
Just as Breanna said, I find it easiest most of the time to just make it work. Fries and salads are usually the safest options, just be wary of cheese on the salads. One warning to always remember is to be very careful with vegetarian meals. Vegetarian meals are rarely good for PKU diets because vegetarians need the same amount of protein in their meal without the meat, while PKU diets need considerably less protein from the meal. As a result, vegetarian meals are usually loaded with cheese, beans, etc. so just make sure to double check.
When I go out to an italian restaurant I usually bring some of my low protein pasta along and when I explain my situation the waiters and staff are always very understanding and I have only been turned down for it once in the past 6 years. Or if you have a relatively high allowance for phe and you stay low that day if you go to a mexican food resaurant most of them will have a vegetarian fajita or burrito, just make sure they don't put beans or cheese on it
Ethnic restaurants! It's usually different from the standard fries or salad. Just do a little research in advance. Indian & Thai restaurants have lots of vegetable options. Some Latino places can be pretty veggie friendly too. Puerto Rican restaurants with jibaritos are my favorite. Jibaritos are basically sandwiches with fried plantains as the 'bread' (plantains are pretty low pro) — ask for a vegetarian version with no cheese. Mediterranean restaurants have good rice & veggie dishes also. If your child is very sensitive to protein, you can call in advance and ask to substitute regular rices and pastas for the low pro versions.