Food-service directors in Wisconsin say they already are preparing to implement new federal school nutrition guidelines, which will take effect in the fall. However, officials say they face several challenges, including encouraging students to eat healthier foods -- such as Brussels sprouts -- and keeping costs low. "This is a real challenge," said Oshkosh Food Service Director Peggy West. "I can write a perfect menu. The question is writing a menu children will eat that will cost roughly $1 to make."