Holy Crap - Look at Jessica Simpson!

This picture from Us Weekly shows Jessica Simpson's dramatic weight loss. She now looks skinny but not unhealthy with her 20-pound weight loss.

Us gives credit to celebrity trainer Harley Pasternak, who is the author of 5-Factor Diet and Fitness. He also trained Katherine Heigl, Sophia Bush, Mandy Moore, and Vanessa Williams.

I think we girls know the real reason - a break up provides great motivation to get to the gym!