In the process, the actress put on weight and began to suffer from dizzy spells. "My blood sugar went out of control. Diabetes runs in my family so I went to see my doctor," she says. "He was like, 'Buck up,' and it was sort of the wake-up call that I needed to hear."
RefreshedWhile Vardalos ignored her physician's suggestion of a trainer or nutritionist, she did create her own diet program, consisting of three low-glycemic meals a day, four snacks ("I always try to eat a protein with a carbohydrate") and long daily walks.
"I'm not one of those people that can suddenly start running and hire a Pilates trainer, it's just not my thing," says Vardalos. "The walks helped clear my head. I was weighing myself once a week, just trying not to be obsessive about it. I just wanted to feel better; I wanted to feel healthy."
Reducing her caloric intake by half, Vardalos also routinely tried on her clothes to keep herself motivated. "I would just stand naked in my closet and try things on," she says. "I didn't want it to be about losing weight, or what I looked like, but how I felt. The reward was how much energy I was gaining every single day. I could feel myself coming out of my period of grief. I felt refreshed."
New MomNow the mother of a 4-year-old little girl, whom she adopted last year, and with two films due out this summer, My Life in Ruins, on June 5, and I Hate Valentine's Day (which she also directed) on July 3, Vardalos says she has never been happier – or healthier.
"It was never about that Hollywood pressure to lose weight, I laugh at that. It was always just an issue of health," she says. "Some people have been calling it a comeback, I actually call it a resurfacing."
For more on Vardalos's weight loss and tips, pick up this week's issue of PEOPLE on newsstands now.
See how Nia Vardalos’s dog helped her lose weight