Effective Nudges for Encouraging Kids to Eat Veggies

I am in the airport lounge in Frankfurt, Germany.  Having just eaten a tasty jelly doughnut, I thought I should post this NY Times piece  which highlights that kids are throwing away the healthy veggies they are being served in school.  Are the young environmentalists more likely to eat them?  What nudge would Cass Sunstein suggest in this case to encourage kids to eat right?   Can schools encourage habits that are not being pursued at home?  A good social scientist should run a field experiment here where the healthy menu options are randomly assigned across schools and somebody secretly monitors to see which kids actually eat the veggies.  Does eating a balanced diet as a kid help to shape your later environmental views as an adult voter?