We've always loved Hilary Duff because she's true to herself - she doesn't slut it up hard or eschew eating just because other celebs choose to.

But while our girl added a boyfriend in NHL star Mike Comrie, she has shed some pounds in the past year, gaining a more svelte figure.

This celebrity's weight loss secret: Pilates.

Combined with reasonable dieting, Hilary Duff, 20, says she has seen her body transformed by the exercise regimen.

"I was a gymnast before, so I was a bit more bulky in the past. [Now] I have leaner longer muscles, my strength is up," she says.

Besides Pilates workouts three times weekly "for flexibility and toning," she gets her cardio boost from doing Piloxing.

That's a combo of Pilates and boxing! Sounds cool!