Well done, Kelly Osbourne

The former reality star from "The Osbournes" and daughter of Ozzy and Sharon Osbourne has dropped over 50 pounds — and it's not thanks to any super secret diet or quick fix over-the-counter supplement. As the 26-year-old says, it all comes down to simple exercise and eating well. 

"I used to eat chips and cookies and drink soda all day long," she told Shape magazine. "I had to start making better choices. Now, when I'm full I stop eating!"

Osbourne appears on the cover of this month's magazine looking svelte in a red bikini and weighing in at 112 pounds. She said that it took appearing on ABC's hit show "Dancing with the Stars" to fully understand what she was doing to herself. 

"I'd fill up on French fries and pizza all day and wonder why I wasn't losing weight. In the very beginning, I kept getting sick during rehearsals because I was eating such terrible, fatty food and feeling so exhausted."

Kelly's dancing partner, Louis van Amstel, eventually pointed her in the right direction.

"He made me eat turkey burgers and salads and explained to me that a high-protein, low-carb diet would keep me energized," Osbourne said. "Then I started losing weight and realized, 'Oh, it's true what they say: Diet and exercise really work!' "

Osbourne also used plyometrics, which involves high-intensity jumping and other powerful movements to rock your muscles into shape. "It's a killer — it hurts so much," Osbourne said. "But when you walk out of there, you're like, 'I can't believe I just did that and my body looks this good.' "

Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.

Kelly Osbourne: Diet and exercise really work!
Reality star appears on the cover of Shape magazine in a bikini after dropping 50 pounds.