I lost weight on a tour that I did in 2007 for precisely the reason that Crankin mentioned. I had trouble eating lunch and didn't compensate enough with mid-ride snacks and at other meals. I loved how I looked when I got back (I got down to my lowest weight since 1996), but I also felt kind of puny, presumably because some of what I lost was muscle mass. So, that's my caution to you. Losing 10 pounds of fat sounds great; losing 10 pounds of muscle not so much. Plus, even with fat loss, it means that you aren't fully refueling your body. Doing that for a few days of riding doesn't sound so bad, but I wonder about the toll that it would take over the course of a cross country tour. I'm hoping that some of the ladies who do ultradistance events will chime in here with their perspective.