Recently I realized that my daughter Celia, a third grader, was sometimes choosing not to eat the food my husband was packing in her lunch. She would trade with another student, give it away, or not eat it at all. Some days when we picked her up from school she would complain of having a headache, or feeling sick to her stomach. She wanted to stop for a snack on the way home-usually something sweet. I suspected that she was not eating enough of the nutritious foods her growing body needed.