HOLLYWOOD, Calif. — Despite admitting to not having a workout plan, Rebecca Romijn has shed nearly 60 pounds since giving birth to twins four months ago.

"I think within the first three weeks, I took off like 35 pounds without doing anything!" the 36-year-old actress told 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."

The "Ugly Betty" star and her husband, actor Jerry O'Connell, welcomed their first children - Charlie and Dolly - in December. While Romijn has being losing weight minus exercise, she does confess to one secret - breastfeeding!

"Breastfeeding is the very best diet I've been on," she admitted. "It's amazing. 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."

While she said her twins are "both just gorgeous," Romijn acknowledged that it will be some time before her body is fully back to normal.

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