It's the oldest admonition in parenting: "eat your vegetables." A study published in today's American Journal of Public Health found that teenagers won't, particularly when their schools give them the option of vending machine food and fried potatoes. Researchers at the University of Minnesota studied the eating habits of 7th grade students at 16 schools in Minneapolis and St. Paul. They found teens in schools with vending machines skipped more of the food they should eat daily, compared with their peers at other schools. Professor Martha Kubik (CUE-bik) was the lead author of the study. She says the report proves just how much influence a school's food offerings can have on students' health.