Buying new clothes that fit the body you have doesn't mean you're giving up on getting fit or being healthy! In fact, I'm pretty sure I've read at least anecdotal stories that people are motivated to start or continue exercising simply because their new clothes fit them so well, it was like an instant weight loss.
I'm another one like AJ (well, not petite) but such that 5 lbs makes a huge difference in how things fit (particularly around the tummy). It was an interesting excercise yesterday trying on dresses at Macy's. The small size made me look hippy and a little pregnant, the next size up was like - *wow* - I look pretty good! You deserve to feel *wow* when you look in the mirror - get thee to a shopping mall!