I would like to share my favorite fruit salad in my area.
You can try out that in a place called “Nutri-Frut” which is located in the downtown of Encarnacion. It’s about 20 minutes from the airport and about 2 minutes from the bus station.
My recommendations is to go there during dinner time because you can eat inexpensive and healthy. The fruit salad starts from Gs. 10.000 which is about $2 and you can eat with a vegetable sandwich. They also make special salad or deserts like the açai wich I think you would like it.
I am sure that you will be full when you leave. They accept only Guarani (paraguayan money) or Debit/Credit Card.
Enjoy!