09/23/2013 at 02:00 PM EDT
It's hard to believe it, but there was a time when Jessica Alba
was unhappy with the way she looked.
"I was a lot more critical of my body when it was probably pretty awesome," she admits in the October issue of Health
"Why did I not ever wear jean shorts? That's so crazy. I was so skinny. I didn't have any cellulite … what was I thinking?"
But after she had two kids
– daughters Honor, 5, and Haven, 2 – the actress became more accepting of her body.
"I was more willing to wear short skirts after I had my kids. I never wore them before. Ever. I was so self-conscious," she says. "Now I'm a lot more confident
in my skin – because who cares? At the end of the day, it's so much time spent on something that really doesn't matter that much."
Alba, 32, credits the way she looks today to healthy eating (she avoids processed foods and starts the morning with a green juice drink that includes veggies like kale, spinach and celery) and interval training, but after she had her second daughter
in 2011, there was something else that helped her get back into shape – a corset.
"Your muscles are completely stretched," she explains. "[The corset] gets the muscle memory going quicker. It's just to get our body back. Because everything is everywhere!"