06/16/2008 at 01:00 AM EDT
"When actresses lose weight, people can think they're anorexic. It's important to me to say that's not the case here," says Kristen Johnston, 40, acknowledging that, yes, she lost more than 60 lbs. in the last year and a half. After 3rd Rock from the Sun
ended in 2001, Johnston starred in more than 15 films and plays, enjoying the "endless debauchery" that can accompany that life. "After a show, you're so hopped up you have a couple of drinks with friends. 'Yeah, I'll stay for another round!'" That, plus a diet of "pizza, BLTs and fries, dinner at 11 p.m.," caused the 6-ft. star to "balloon" from about size 6 to 12. "I was miserable." Then, in December 2006, while in a London production of Love Songs
, she suffered a burst ulcer and spent weeks in the hospital, where "you take a hard look at your life." She stopped drinking alcohol and added more vegetables, oatmeal, salads with salmon and—"crazily enough," says the new baker—homemade fruit pies. Focusing on her health, not the scale, made the weight loss easy, she says. Biking in New York City also helped. Though she may try to gain back 6 to 8 lbs., "I think it looks great. I feel amazing," says Johnston, who just shot Bride Wars
with Kate Hudson
. "I no longer stress about my body. I'm in a happy place."