Yes, I usually take at least a good portion of the food I expect to use from home and yes, most of my tours are very short- normally only weekends.

My original point was that I`m bad about lugging too much food. My subsequent point was that carrying only one meal around here would range from silly to outright dangerous. There are short tour routes that would allow that kind of packing, but not many. More often than not, somewhere along the course of a weekend trip is a span of longer than one meal`s worth of time without services. Occasionally, there will be no services for more than 24 hours. The most extreme case I`ve had from my own touring experience involved carrying water for about a hundred miles of dirt road (knocking on a door was not an option, nor was filtering or treating water). Keep in mind also that just because there`s a store at a certain location on one trip doesn`t mean it won`t be boarded up the next time you pass through.

Anyway, this weekend`s trip had a reasonable food and water available and I resisted the urge to overpack. I`ve often overpacked in the past despite having reliable services on route.

EDIT: This is admittedly not my average trip, but it does provide a good example of why I don`t have the have the same view about buying along the way.
http://www.crazyguyonabike.com/doc/gerlachride