In fact, the actress, 32 – who doesn't attend Weight Watchers meetings, but is a member of the group online – maintains that she's never been on an actual diet.
"I was so shocked when it was this whole, 'Ginny's been on a diet since she was 9 years old!' I was like 'No!' I've never had body issues, I've never had an eating disorder," she tells PEOPLE. "I've never had to go on a diet and that's because of Weight Watchers."
Goodwin, however, says she was an overweight child, which led her to the program. "I began to identify myself as fat." Goodwin says. "At 9 years old I weighed about 10 lbs. less than what my weight is at 32. I needed to get help."
"I ended up going to my mother crying,"she recalls. "With the counseling of my family doctor, my mother ended up turning to Weight Watchers and their children's program. I went to weekly meetings, got counseling and would exercise with my peers who were my size. It was the first time I saw a proper children's portion size, and it wasn't two burgers, it was one."
Takes TimeLosing the weight, recalls Goodwin, "was extremely easy to accomplish." But she adds, "It takes time because you lose the weight slowly. It's a healthy way to do it."
And she's kept the weight off with ease over the years. "You don't have to go through that horrible yo-yo cycle of binging," she says. "I've always been able to satisfy my cravings; it's just a matter of balancing."
It saddens her to see her peers struggle with weight. "I pulled an actress friend aside and I said, 'I get it. I get what it is that you're trying to do, but there's being healthfully skinny and then there's starting to look like a scary alien cat,' " she says.
Goodwin has a not-so-flattering name for the diet secrets of some of the rich and famous. "I call it the 'Cocaine and Cigarettes Diet' in Hollywood," says the actress, who also doesn’t believe in a low-carb diet as a permanent solution. "I see girls who haven't had a carbohydrate in three years. The second you go back to eating right, you're going to put that weight on. You eat one piece of bread and you are screwed, lady!"
Goodwin, who became engaged to actor Joey Kern last month, concedes that she has lost weight since getting to Hollywood.
"At lunch the last day [of shooting Big Love] they showed the pilot and I was shocked at how much rounder I looked. We shot the pilot almost a decade ago when I was just out of college," she says. "I think it took me a long time to lose more baby-fat. And yes, living in L.A., you exercise a lot more because it is gorgeous year round. I do a lot of hiking. I can see that my habits have changed."
In the end, Goodwin credits her mother for her healthy approach to life. She looks back to the day when she told her mom she was fat. "Her reaction was not, 'Oh, I'll help you get skinny," says Goodwin. "My mother's reaction was, 'Why don't we all go and learn a little more about our health."