Jennifer Hudson on the cover of Feb. 2012 Good Housekeeping

In an interview with Good Housekeeping, Jennifer Hudson dishes on her heavy past, her son and life after shedding 80 pounds.

These days “American Idol” premature cast-off Jennifer Hudson is known just as much for her striking physique as her Grammy-winning set of pipes. You’d have to have been living under a rock to miss the 30-year-old star’s Weight Watcher’s ads on TV during the past year. Hudson is absolutely everywhere, including on the cover of February’s Good Housekeeping, talking up the weight-loss program that so drastically changed her life. Now 80 pounds lighter, Hudson easily remembers a time when her weight was a roadblock for some, beginning with those she encountered on “Idol.”

“Early on, I remember one of the musical directors telling me that everything about me was too big–my voice, my size, and my personality,” she remembers. But Hudson says she just asked, “‘Isn’t that what being a star is?’ Stars are larger than life!” Despite her undeniable talent, Hudson concedes to missing out on opportunities due to her weight, which peaked at 236 pounds. After failing to book a gig as a backup singer for Barry Manilow–despite the legend’s own excitement over her audition–the Oscar winner admits, “It took me years to finally realize that I didn’t get the job because of my size.”

And while many a young girl might be hypersensitive about her size, Hudson says she was “the skinny one” in her own family. Even her hometown of Chicago swallowed up the fact that she had a weight issue. The singer says, “But then I’d go to another city, and it was real culture shock. I’m like, Huh? Wait a minute–I’m a big girl?”

A lifetime of home-cooked family meals showcasing fried chicken and pork chops didn’t help. It wasn’t until Hudson and fiancé David Otunga had their son, now 2, that Hudson decided to take control of her weight. In her new book, “How I Changed My Ways and Lost What Weighed Me Down,” she gives her own account of a history of yo-yo dieting.

“Everything changed the day my son, David Jr., was born,” she tells Good Housekeeping. “Motherhood brought tremendous responsibilities–but none greater than the obligation I felt to get healthy and be there for my son … I needed him to grow up with a mama who always would be there for him by caring enough about herself to take control of her health and her eating.”

Parenthood is the greatest of motivators–even bigger than impending superstardom, it would seem. Sure, Hudson has learned to curb her cravings and choose healthier options, but even she says she can’t say no to chocolate. “I’ll find a calm, peaceful moment, and I’ll sit back and eat my chocolate, which I make sure is really good quality,too,” she says. “Quality over quantity!”