What does a dancer eat to stay in top form? In the case of Michele Wiles, principal with the American Ballet Theatre, whatever she wants. It wasn’t always so: When she attended boarding school at the age of 11, her ballet instructors kept close guard over her diet. “They made sure we weren’t eating fattening foods,” Wiles recalls. “We got weighed once a week and were told if they thought we were overweight. When I got out of that and moved to the city, I ate nothing but junk food.” So what fuels a dancer for a spate of upcoming performances?