Jessica Simpson weight loss: 'Jessica can lose 7 pounds in a week'

Photo/AP

In a recent report from OK! Magazine, Jessica Simpson's weight loss has totaled 12 pounds, saying the star has dieting down to "a science", mastering the ability to lose 7 pounds in just a week.

While the number may be fuzzy math since Jess's true digits haven't been revealed, the magazine had Jeff Halevy analyze the star's physique.

"Looks like she's lost about 12 pounds," says the CEO of Halevy Fitness to OK! Adds a source to the mag, "Jessica can lose seven pounds in a week when she puts her mind to it. She has it down to a science."

Simpson who has been publicly mocked by Burger King (and defended by sis Ashlee!) for her weight loss, has slimmed down - But but it's not just from a new diet, despite reports from the mag. Simpson has recently re-teamed up with celebrity trainer from her past Mike Alexander, who's got Simpson doing lunges and glute work to the point of exhaustion.

Alexander, who helped Simpson get her Dukes of Hazzard body (shown above), said in an interview with SHAPE magazine he can't put enough emphasis on doing lunges to get the body fit. To read more, click here.