Mariah Carey: I Lost 30 Pounds of Baby Weight in 3 Months!

"Shake It Off," indeed!

Six months after welcoming twins Moroccan and Monroe, Mariah Carey has lost 30 pounds -- and shows off her toned legs and flat stomach in size-6 short-shorts on the stunning new cover of Us Weekly, out now.

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"I gained an enormous amount of weight," the Grammy-winner superstar tells Us of welcoming her son and daughter April 30 with hubby Nick Cannon.

How'd she slim down? Beginning in July, Carey buckled down with a nutritionist and a workout plan from Jenny (formerly Jenny Craig), keeping to a 1,500-calorie-a-day menu and thrice-weekly workouts.

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"I feel incredible," the "Fly Like a Bird" singer tells Us, three months after her body transformation began. She and Cannon, 31, famously struggled to conceive their twins (born via C-section at 35 weeks) after a heartbreaking miscarriage.

"It was a huge blessing to be able to have the babies," Carey says, "But I felt trapped in my body because I couldn't move."

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Adds the once-again svelte star: "I'm proud of how hard I worked to get my body back...I had to do this for me."

For much more of our cover story on Mariah's incredible transformation -- her body ups and downs, a sample menu and workout plan, adorable new snapshots of the babies, what Nick thinks of her new body and whether she'll lose more weight -- pick up the new Us Weekly, on stands Friday!

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