Susan Powter is an alchemist for the '90s: She's turning anger into gold. Her fury is directed at a diet industry that tells women they have to follow strict regimens to look as thin as Cindy Crawford—and at the men who dump them when they don't. But Powter has gotten even. Less than a decade ago, as she tells it, she was an obese, depressed mother of two whose philandering husband had walked out on her. Today, at 36, she is a hard-boiled, hard-bodied fitness guru, who, through her infomercial Stop the Insanity! sold some $50 million worth of weight-loss products this year—an all-time infomercial record.

Seizing the moment, Powter has amassed an empire that includes lectures, seminars, a video, a best-selling book and, potentially, a talk show and a starring role in a Linda Bloodworth-Thomason sitcom. Though many others have tapped into Americans' obsession with their bodies, Powter offers a new, feminist spin: Don't just get mad, get fit.

Powter claims to have discovered her program the hard way. When her marriage unraveled in 1984, she ballooned to 260 pounds (though her estranged brother Mark disputes this figure) and then suffered through a number of failed diets and exercise-class humiliations before shedding 133 pounds by eating large quantities of low-fat foods, working out regularly and doing deep-breathing exercises. To many, Powter's inspirational flab-to-fitness saga is as big a selling point as her actual program, which is similar to those advocated by many nutritional experts.

Currently, Powter rents a Dallas duplex in which she, her second husband, musician Lincoln Apeland, and her sons, Kiel, 9, and Damien, 10, live upstairs, while her first husband, Nic Villareal, and his wife live downstairs. "I pay for it all," says Powter. "I like it that way." Readers of Powter's book—also called Stop the Insanity!—are promised even more. "Here's why I do what I do," she writes. "So that the women of this country can get well and take over the world."