Fruit and vege are a good idea. Have you tried taking your child/ren shopping with you? (I realise this could be tricky) Show them the fruits and veges section, and ask which three or four different kinds they can choose. It's a pity supermarkets don't have regular samples to encourage kids to try. You could make fruit or vege on a stick. Hollow out a pepper and fill with veges they like, or hollow out an orange and fill with fruit, cover with gladwrap. Google is full of awesome lunchbox ideas. Good luck