New mom to twins Dolly Rebecca Rose and Charlie Tamara Tulip, born Dec. 28, Rebecca says her secret to postpartum weightloss was breastfeeding. After gaining 60 lbs. during her pregnancy, ““Extra!”, “I think within the first three weeks, I took off like 35 lbs. without doing anything,” adding, “[It's] the very best diet I’ve been on.” Her second secret? Spanx!