I'm on a diet and have lost a few pounds.?

Have allot more to lose, but people are starting to notice and are, for the most part complimentary. My supervisor though, has made it her mission to monitor my progress, and quiz me on how much I've lost, what I've eaten, what I plan to eat, etc..... The questions are endless and getting really tiresome. I really really want to end the questioning but don't know how to get her to back off. I try to be vague, and change topics as quickly as possible but she's like a dog with a bone. Any suggestions on how to tactfully get her to stop with the questions?