Funny girl Rebel Wilson flaunted serious weight loss at her "Pitch Perfect" co-stars' wedding. Wilson, who brought down the house in "Bridesmaids" and "Brothers Grimsby" shared the startling reason for her weight gain and secrets to weight loss. Rebel joins many other big name celebrities in her quest to get thin.

Rebel Wilson: fat people are funny

Most people who gain weight don't choose to. It happens by poor lifestyle choices, overeating and lack of exercise. But Rebel Wilson actually chose to get fat because in her words, fat people are just funnier.

But Rebel found obesity was no laughing matter. Sure the "Bridemaids" star made folks howl with laughter. They almost wet themselves over her hilarious performance in "The Brothers Grimsby." Will they still find her funny now that she is thinning down? Hopefully this won't come back to bite her as formerly obese, now slender Melissa McCarthy found. McCarthy lost her obesity-celebrating show "Mike and Molly" because she wasn't fat anymore. There's a takeaway in that, however, and it's not to stay fat. It's about self-confidence which goes hand in hand with weight loss. The more you lose the better you feel.

Obesity is no joke

So people kept laughing and Rebel Wilson kept gaining, but she no longer found it funny to see the scale upping to dangerous levels.

Diseases like Type 2 diabetesand heart failure begin to show up. Getting a part in the London West End production of "Guys and Dolls" was the excuse she needed to lose weight. In the nightly performances Wilson acts and dances her butt off, literally. Doing theater is better fitness even than chef Rocco DiSpirito and his "cook your butt off" weight loss plan!

Rebel is also a fitness powerhouse. At a fitness retreat she dropped a record-breaking eight pounds in four days, thanks to super-intensive workouts. Wilson also attributes the weight loss to daily massages. And there's some merit in that--massage helps muscles relax and work more efficiently. You're not so tired and can put more energy into workouts. Massage also helps reduce swelling and water retention. Rebel hasn't put a number on how much she's lost but her Instagram updates reveal it's a big one.