Some stars, like Oprah Winfrey, Kirstie Alley, Jessica Simpson, and Christina Aguilera, are as famous for their ever-changing bodies and weight ups and downs as for their talent
Spears, who once bragged that she did 1,000 sit-ups a day, was in tip-top shape as a young pop star. As she got older and had kids, however, she struggled to stay in control of both her physical and emotional well-being. "I have had to work hard at getting [my body] back to where it used to be," she told Glamour magazine in a January 2009 interview. "I used to be obsessed with working out...Now, three days a week is cool, even two."