By Alexis Tereszcuk - Breaking Celebrity News Entertainment Editor

There’s no better weight loss exercise than dancing.

Opera singer Katherine Jenkins is sizzling on stage each week on Dancing with the Stars and she’s working so hard that she’s dropped a whopping 21 pounds in the first three weeks of the competition!

“I've lost a stone and a half (21 pounds),” she said about her slimmed down figure. “I'm burning so much energy now that it’s hard to put the weight back on.”

Katherine and her partner Mark Ballas have consistently topped the leader board on DWTS, and all of her hard work is shown in her killer new body that she’s going to work hard to maintain.

“But I like to be curvy so I’m trying not to lose any more,” she told the Daily Mail about her svelte new look. “But I do want to be healthy, too - there are so many skimpy costumes to wear. That scares me.”

Earning a respectable 24 in Monday night’s competition, Katherine will most likely stay on the dancing competition show for some time, and she’ll definitely be able to maintain her new super sexy bod!