It's Rude Not To Eat

It's rude not to eat the food made for you. There's no way around it. Are you training your child to only like hot dogs?

Here's a good little article on raising kids to eat well. Your kids aren't just picky. They're rude. And you let them be that way.
In the book Bringing Up Bebe, Pamela Druckerman observes the way that French children are expected from the youngest age to eat what they are served and develop a varied and sophisticated palate, as well as excellent table manners that enable French parents to dine out with children sans spaghetti flying through the air. She contrasts this to the very American parenting style of raising “picky eaters” on ramen and French fries. American parents are basically hardwiring their children to have food aversions by allowing them to refuse foods from a young age. American children typically aren’t the best restaurant company either…
I often get on my horse and say that children are picky because they're expected to be. One family does not a parenting philosophy make, but I can tell you that it never occurred to our kids to be picky. That doesn't mean they like onions, necessarily. But it does mean they're good and polite eaters.

This thing is not too far for you, and it's not too late.