Be cool!

Hola and Hello! I am translating a series of educational brochures on health related issues for school age children. I am a bit stuck in "Be cool! Eat smart! Make smart choices and Chips and sweets are treats" I need some neutral Spanish translation and all I come up with is some sort of slangish terms. Help!
Thanks

Hey there.. Ive been frying my brain trying to come up with sth, and I also can only think of slang Argentinian lines.. Like canchero... But after a while i thought.. Hasnt cool become an international term? Couldnt you keep it in English?

I know!! I came up with Se listo! Come bien! Sounds a bit amateurish for my taste, but at list flows better than the many more I thought before. I would use canchero too ;)
I like the idea of using cool and a new Spanish accepted word but... Se cool! ... does it sound good? I need to clear my mind and get back at it with a refreshed brain.
Thanks a lot for your reply, it reassured me that I am not alone in this crazy translating boat :)
Dani

I think that be cool in this case is more related to "wise" or "clever" rather than "canchero". Something more like "Sé listo", "Aliméntate bien"
Hope it helms

"Onda" can also be applied in this case: "¡No pierdas la onda!" ¡Aliméntate bien!" How does that sound?

Thank you everyone! I like "No pierdas la onda" a lot!!! This is the first time I use this web site and I can tell I will be back ;)
Thanks to all who replied, I really appreciate your input.
Dani