Jennifer Hudson's dramatic weight loss is no secret -- and thanks to her yearlong stint as a Weight Watchers spokesperson, neither is the way she's accomplished her fitness goals. And now, thanks to a bit of digital trickery, her latest Weight Watchers commercial lets us see just how much she's changed.

Jennifer duets with herself in the new clip, standing side-by-side next to her old body while the two Jennifers perform her 'American Idol' song 'I Believe in You and Me.'

It's one thing to know how much weight a person has lost, or to realize they're quite a bit healthier than they used to be. But as anyone who's ever watched an episode of 'The Biggest Loser' could tell you, there's nothing quite like seeing someone's slimmed-down physique standing right next to a picture of what they looked like at their heaviest -- and for proof, you need look no further than the svelte-and-fabulous Hudson as she harmonizes with her old self.

Watch the commercial below. Pretty impressive, no?

Watch Jennifer Hudson duet with herself on 'I Believe in You and Me'