The rate of obesity in children ages 12 - 19 has tripled, and for ages 6 - 11, doubled in the last 30 years. My own 18-year-old students last year were not among the slimmest I've ever seen. One day we got into a discussion about chores in class. What I heard from them was disturbing: approximately half had never had to do much more than wash the dishes and make their beds at their own home. Why? Here's what I learned from them: -Many of their parents live in suburban homes where the yardw...