On one hand, celebrities have it pretty good: they fly in private jets, live in multimillion dollar mansions, and work in some of the most exciting industries imaginable. On the other hand, they are under constant and sometimes relentless scrutiny over how they look. The world of entertainment not to mention the millions of fans who live vicariously through celebrities and expect them to be nothing less than perfect can be cruel to those who slip and pack on a few extra pounds.

These 17 celebrities know a thing or two about public scrutiny, and have worked their butts off, literally, to lose weight and get into incredible shape.

Jennifer Hudson

After teaming up with Weight Watchers in 2010 to become their spokeswoman, Hudson lost an amazing 80 pounds on their program. And, even more impressive, she has managed to keep the weight off. In an interview with Redbook magazine in 2012, Hudson acknowledged, I got used to being plus-sized and knowing how to be that. I keep thinking that I probably need an extra-large or a large and the stylist is like, No, you need a medium or a small.