Rebecca Romijn's Post-Pregnancy Weight Loss Secret

Rebecca Romijn has shed those extra pregnancy pounds after giving birth to twins in December - without a workout plan!

The "Ugly Betty" beauty dropped nearly 60 pounds in just four months without hitting the gym.

"I think within the first three weeks, I took off, like, 35 pounds without doing anything!" she tells Extra. "I haven't been able to work out that much because I have twins. It's impossible to get back into a regular schedule," " says Romijn.

So, what's her secret?

"Breastfeeding is the very best diet I've been on. It's amazing," she says. "It's like you have to eat 5,000 extra calories a day or you can't produce enough food for them. So, that's been fun as well."

But the new mom admits she still has more weight to lose.

"I'm not pretending to be back to the shape I was in beforehand anyway. I still have a ways to go.We've got Spanx underneath almost everything." she says.

Romijn and husband Jerry O'Connell welcomed their twins Dolly and Charlie in December.