Alessandra Ambrosio reveals she had only 3 months to lose her baby weight in 2008

Having children changed how Alessandra Ambrosio felt about modeling.

The Victoria's Secret supermodel opened up to Net-a-Porter magazine recently about doing a fashion show just three months after having her first child in 2008.

"Your body will never go back to exactly what it was before pregnancy, whatever people tell you. It can't," she told the publication. "But I think I have a better body now than before I had kids. It's partly because I work out, whereas before I didn't, but also to do with the shape – it just looks more formed now and I feel better about it than I did."

WATCH: Alessandra Ambrosio Poses Fully Nude for Maxim

"Not that it was easy getting back into shape post-pregnancy," the model and businesswoman, who turns 35 on Monday, explained. "After having Anja I only had three months to lose all the weight [before doing the 2008 Victoria's Secret show] and I was on this 1200-calorie-a-day meal-delivery service that I hated. I couldn't do that again."

Ambrosio has two children with partner Jamie Mazur -- 8-year-old Anja and 3-year-old Noah -- and during the interview she revealed that becoming a mother changed her perspective on posing in front of the camera.

"I used to be 100 percent comfortable on lingerie shoots – then I had a child, and it was more of a mental shift than anything else," she said. "Somehow it felt a bit weirder to be in lingerie once I was a mum."

Despite the feelings, Ambrosio hasn't stopped doing intimate shoots, such as her nude shoot with Maxim last year.

PHOTOS: Hollywood's Hottest Bikini Bods!

"Although I did that cover for Maxim last year [naked but for a strategically placed newspaper], you don't see anything," she said. "When my daughter saw it, she asked, 'Mummy, why do you have no clothes on?' And I said, 'Mummy actually has a G-string on – it's just so small you can't see it.'"

Ultimately, she determined that the key is to feel good about yourself, inside and out.

"If cosmetic help makes you feel better about yourself and gives you confidence, then great," she said. "None of us can ever be sure of what we're going to end up wanting to do in the future. But it's important to take care of our mind and spirit, too, not just the outside."

WATCH: Cristiano Ronaldo and Alessandra Ambrosio Pose Nearly Nude on Sizzingly Hot 'GQ' Cover

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