Bruce Fredericks / Retna Ltd.
Bruce Fredericks / Retna Ltd.

Celeb moms who suddenly look skinny weeks after giving birth? Not realistic for her, says Tori Spelling.

"I read all the magazines -- I know how all the actresses look great weeks after having a baby, and that doesn't happen [to me]," the reality star and author (her new book, "Mommywood," is on sale now) said during a visit to Us Weekly's New York City offices.

Spelling, 35, gave birth back-to-back to Liam, 2, and Stella, 11 months. "All I know is being pregnant and losing baby weight," she joked.

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"With Liam, I gained 40 pounds, and I did lose the weight, but it sucks to have to diet and exercise," Spelling said. "With Stella, I gained 40 pounds [too], and I started back to work four days after having her."

The weight came off easier the second time around, she said, even though she skipped the gym.

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"For me, spending one hour away from my kids when I did have days off and downtime, I wasn't going to spend it in the gym," she said. "That wasn't an option."

She and husband Dean McDermott "started cooking together and using organic produce, and making it more of an family experience.

"The pressure came off. The weight came off a lot quicker when I wasn't like, 'Oh, I have to follow this diet regime!' It was just easier doing it the natural way," continued Spelling.

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For more details on Spelling's feud with her mom, what she thinks about finding love on sets of "movies of the week" (as both Eddie Cibrian and LeAnn Rimes did on Lifetime and she and McDermott did on "Mind Over Murder") and what's next on "90210" -- watch the video at Usmagazine.com.

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Photos: Tori Spelling