"Do not play with the food!"

Translation: Lek inte med maten!

[Aristotels]

"spela inte" is not correct?

[devalanteriel]

No, you'd spela a game or a sport. So unless you do mean don't play a game with your food, it is incorrect.

[InvertedGo]

Like oreo and marshmallow checkers...or chess.

[Den_Oslagbara]

Could you say use "ej" instead of inte? How would they differ?

[devalanteriel]

Yes, you could. Generally speaking, ej is the much more formal version of inte. I don't recommend using it in any normal context.