Okay, so maybe it's not a surprise that a 5'9" underwear model would need only three months to lose the 45 lbs. she gained while pregnant. What is surprising is that, for Alessandra Ambrosio, doing so "was really hard!" she insists. "I'd been eating everything I wanted—everything!—and once you get used to that, it's hard to stop." Of course, being booked for the Victoria's Secret Fashion Show on Nov. 15 (the show airs Dec. 3 on CBS) provided plenty of incentive. Out went seconds of beef stroganoff and her daily Häagen-Dazs; in came "lots of salads, brown rice instead of white and tiny portions," she says. Ambrosio, 27, also exercised for 2 to 3 hours a day, doing 45-minute treadmill workouts along with squats and lunges, while her mother or sister watched daughter Anja Louise (whose father is Ambrosio's fiancé, entrepreneur Jamie Mazur, 27). But now that she has her old body back, Ambrosio is only doing light training and allowing herself some treats. "If my friends and I go out, I'll have a glass of wine," she says. "And I love chocolate!"