OK! Exclusive: Alanis Morissette's Slim-Down Secrets!

Less than a year ago, Alanis Morissette found herself in a heavy situation: the once-svelte rock star had packed on weight, and the processed food she’d been eating left her feeling unhealthy.

Determined to get back on track, Alanis turned to Dr. Joel Fuhrman’s book Eat to Live, a plan that recommends consuming fruit, vegetables, beans and nuts, and avoiding meat and dairy products.

Alanis’ vegan diet — one of the more popular in Hollywood these days — has helped her shed 20 pounds since she began the new regime in September.

OK!: What were you eating that made you gain weight?

A lot of salt and processed grains like bread. I was a sandwich person, and if I had rice, I would pack the salt on.

OK!: Why did you overeat?

All the restrictions and limitations I’d placed upon myself for many years were let loose. I think it was a rite of passage for me. At 21, I was touring with Jagged Little Pill, so I didn’t experience the footloose and fancy-free passage that most people do in their teens and early 20s. My whole life I’ve been overly responsible. So I was fantastically indulgent for a good nine months. I knew it would be a temporary thing, and it was fun. There was a sexiness to my curvier self that I loved.

OK!: Why did you want to find a new eating plan?

Longevity. I realized I want to live till I’m 120. There’s a lifestyle that I am how happily creating that can, as best as is possible, prevent most forms of cancer and other diseases.

OK!: How did you come to choose Dr. Joel Fuhrman’s program?

I went to my favorite bookstore, Banyen Books and Sound, in Vancouver. I saw this book, Eat to Live, and I thought, that’s exactly what I want to do. I wasn’t interested in some fad diet that was unsustainable, like “lose 10 pounds in two weeks.” I don’t believe in diets; I think they’re short-term and a bit of an emotional roller-coaster. So I opened it and flipped through and thought the weight loss is incidental. The primary focus is disease prevention.

OK!: What is your workout routine?

When I’m out on tour, my shows are so physical that that really takes care of it. When I’m not on tour, I do between a half hour to an hour of light weights, running, biking, swimming, probably five times a week. I also love to kickbox and dance.

OK!: What does your boyfriend (attorney Tom Ballanco) think of your weight loss?

He just cares about my well-being. He thought I was sexy at whatever weight that I’ve been. I’ve never felt loved in that way before.