Concern for Santa

Today, Jacob heard a Weight Watchers commercial on the radio.  He said "Mom, why is weight so important?"  I said, "If you have a lot of extra weight on your body, it's really unhealthy and it makes it harder to do things."  He thought for a moment, then said "Well, what about Santa?"  Hmm.  How to respond?  I told him maybe we should leave Santa something healthy this year. He's planning to leave veggies and just one cookie (yipee- my son has learned moderation!)