Even lose 20 pounds in three months.
"It's true," said Sousa, 18, who plays the troubled Latina diva Carmen Diaz in the Rainbow Stage-produced musical, which opens Tuesday night at the Pantages Playhouse.
"I had to cut out McDonald's and pizza. But exercise was the key."
A relative newcomer to musical theatre, Sousa had an ensemble role in The Wave at Manitoba Theatre Centre last October when she auditioned for Fame's director and choreographer Brian Foley.
Foley was immediately struck by Sousa's hoofing talent and vocal prowess.
They were perfect for the character who gets to sing the show's title song, best known for its signature lyric: "I'm gonna live forever."
He told her she had the part if she dropped the weight from her 5-foot-7, 140-lb. frame prior to beginning rehearsals on Jan. 8.
"The character is hot, she's sexy," says Foley, a Toronto-based stage veteran who has helmed 10 summer shows at Rainbow since 1981.
"Stephanie can't just act the part, she has to look the part."
Sousa took the challenge in stride, eager to win her first major role since graduating from the performing arts program at Grant Park High School.
"I wasn't that happy with my figure, anyway," she says. "I just needed something to motivate me."
She cut out fatty foods and stopped eating full meals at 11 p.m. when she came home from performing or rehearsing.
Equally important, she hit the gym daily -- to run, lift light weights, do situps and work out on the roll machine.
"I like the way she thinks," says fellow performer Jeremy Kozielec, who had the lead role of Mark in The Wave and plays the earnest Shlomo in Fame.
"She didn't take offence. She just did what she had to do."
For most of the young performers in Fame's 20-member cast, chasing the carrot of stardom is worth the cost.
That, of course, is one of the subjects explored in the musical, based on the 1980 movie and subsequent TV series about students at New York's High School for Performing Arts.
"Who wouldn't want to be famous?" says Sousa, who has already tried out for Rainbow's forthcoming summer production of West Side Story.
"You read about all those movie stars who say they just want to be left alone. But I wouldn't say I don't want fame until I experience it myself."
Kozielec, 21, says he aspires more to success as a performer than notoriety.
"Some people have fame, but they're not happy," says Kozielec, who may be familiar to Winnipeg casino-goers for his impersonation of pop crooner Neil Diamond.
"If you're happy with what you do, you're successful."
Fame -- The Musical is Rainbow's Stage's latest attempt to target a younger demographic with a winter show.
Last year at this time, the 48-year-old institution, which produces summer shows out of its outdoor domed home in Kildonan Park, mounted A Chorus Line (featuring Sousa in a small role). The year previous, it inaugurated its winter season with a production of Singin' in the Rain.
Fame offers the theatre its best bet yet at appealing to a more modern sensibility.
Developed by the movie's co-producer, David de Silva, it premiered in Florida in 1988, died two years lager, was reborn in 1993 in Stockholm, where it ran for 18 months, then moved to London.
It has never made it to Broadway, but since 1998, there have been more than a dozen touring companies worldwide.
The show has enjoyed strong word-of-mouth from audiences, despite largely bad reviews from critics. "A stupefying mass of clichs" is how the Chicago Sun-Times described a version that stopped in the Windy City in 1999.
Earlier that year, the Washington Post labelled Fame's score, by U.S. pop songwriters Steve Margoshes and Jacques Levy, "one of the least memorable in the history of musical theatre."
Not to worry, says Foley, who claims he has put together a dynamite production, consisting largely of the original book with the best segments of the touring production.
"Our Fame is almost Version 3," says Foley, who has choregraphed some 600 TV shows and directed more than 100 theatrical productions.
"It reeks of dynamic energy, balls and power."