Kristin CavallariThere simply has to be some sort of magical formula in the water in Hollywood, because even celebrity moms who pack on a ton of weight during pregnancy seem to somehow lose it overnight -- making the rest of us feel like a bunch of fat, frumpy women with cottage-cheese thighs and zero willpower.

Seriously -- how do so many famous women manage to bounce right back after giving birth as if they never had a tiny human being living inside their bodies? Take Kristin Cavallari, for example. She just welcomed her son Camden on August 8, making him exactly 2 months old. And this picture of her was taken in New York City just last week -- and serves as evidence that she's already back to her minuscule pre-baby size. (Baby? What baby?)

More from The Stir: Jessica Simpson's Legs Make Us Forget About Her Baby Weight

And Kristin isn't the only famous mom to have given birth in the past year and snapped right back into shape. Take a look at the photos below to see six more amazing post-baby bodies that will make you cringe with jealousy.

How long did it take you to lose your baby weight? (Or are you still trying?)

 

Image via Splash