Mackenzie Wolfson, a natural athlete (top left) and accomplished tennis player who plays on her school's varsity softball team goes through the first activity of every day at Camp Shane, a stretching class. (From the book What I Eat: Around the World in 80 Diets.) The caloric value of her typical day's worth of food in July was 1,700 kcals. She is 15; 5 feet nine inches tall, and 299 pounds.