christina-aguilera-skinny-weight-loss-leno.jpgMargaret Norton/NBC

The incredible shrinking Xtina!

Christina Aguilera appeared on The Tonight Show with Jay Leno on Wednesday evening to promote the upcoming season of The Voice, and we can't even remember the last time she looked this slender!

The 32-year-old singer tweeted, “Backstage at Tonight Show getting ready to chat with @jayleno. xo” We're not sure what she's done to slim down, but she looks absolutely amazing!