Sidibe told "Access Hollywood" she decided a long time ago to be happy with the way she looks.
"It was a long transition," she said. "I'm just grateful that I am there because so many people go through this -- beautiful people, gorgeous people -- don't feel it, don't feel as if they're gorgeous. And I think it's really sad. And I'm glad that I happen to be one of the people who does."
Indeed, Sidibe made no secret about her crush on Justin Timberlake, publicly inviting the singer to be her date to the Academy Awards. On the Oscars red carpet, she flirted with Gerard Butler. After the Oscars, she told a reporter she was "going to hit a Chick-fil-A" and "hit it hard."
"From what I can tell, she's a strong young woman," E! online columnist Marc Malkin told ABCNews.com. "She has a sense of self. She's very grounded. People are judging books by their cover and expecting someone on the shy side. But she's outgoing, sweet, confident. I don't think anyone's going to be pushing this woman around."
Dr. David Katz, an obesity specialist at Yale University, agreed that in the case of Sidibe, one should not judge a book by its cover.
"It is possible to be heavy and happy," Katz told ABCNews.com. "I also think it's possible to be thin and miserable."
Similarly, Sidibe, who appears to be well over 300 pounds, may not be in immediate danger if her weight is not causing any life-threatening illness.
But if he were her doctor, Katz first would want to know if she's healthy and, secondly, if she is truly happy with her size.
"When you see a very high degree of excess body weight, food is usually being used to compensate for something," he said.
Though she may be tolerating the weight well now, Katz said it could become a problem later.
"If weight hasn't caught up with her health, it certainly could," he said.
Sidibe's message that her weight does not define her is a good one, Katz said. But if people interpret from her example that they should not worry about their own weight, he said that would be a tragedy.
"We need acceptance, but we should not encourage apathy," Katz said. "We need to attack the problem without attacking the person."
If Sidibe does continue to pursue acting in Hollywood, she'll find pressure to conform to Hollywood standards, including being thin. Manheim, Latifah, Hudson and "Ugly Betty" America Ferrara all have dropped sizes since starting in Hollywood.
"She's certainly going to have pressure to lose the weight," Jacobs of Us Weekly said.
"I think if she does, that would be tragic, to see her spirit crushed in that way," Fatshionista's Kinzel said.