Tyra Banks says she's "used to being stared at" when she strolls past high-end shops on Los Angeles' Robertson Blvd. But on Oct. 17, as Banks made her way through the neighborhood—her supermodel curves hidden beneath a prosthetic suit that made her appear 200 lbs. larger than usual—she drew a different sort of attention. "It was awful," says Banks, 31, who conducted her fat-for-a-day experiment for the Nov. 7 episode of The Tyra Banks Show. "I would try to make eye contact with people and smile, but 90 percent of them didn't smile back. I got snickers."

Banks—who previously had an on-air sonogram to prove she doesn't have breast implants and shares her psychotherapy on a Nov. 14 episode—got the idea to walk a mile in another woman's plus-size loafers after a recent breakfast with friends. "There was every race at the table, gay and straight," she says. "But when the subject of obesity came up, my friends started talking in a rude way." Poking fun at the overweight, she argues, is "the last accepted form of discrimination."

Banks experienced such disdain first-hand when she went on a series of blind dates in her disguise—and became the first Victoria's Secret model to be rejected by not one, not two, but three guys. (Banks then enjoyed a "gotcha" moment, revealing her identity to three very disappointed suitors.) "The cruelty of people hurt me so much," she says.

Even though she "could take the suit off at the end of the day," the fit, 5' 10" Banks says she'll carry the experience with her. "I'm not in a position to tell heavy people anything," she says, noting she played the role only for a few hours. Her intention is that the fat-suit episode might make some people think twice: "I hope this show will cut down on the cruelty."