"On the contrary, it means I don't really care what they think. By being open on the subject and laughing at myself I become more confident. Yes, I do want to lose weight. But that's because I would like to be healthier, not because of what people are saying about my looks."

Jeffery Schwab, who once founded an improv group in Portland, Oregon of the United States, and who is now a member of Beijing Improv, says the first step in changing the status quo is to get more women on stage.

In English-language performances of Beijing Improv, there are sometimes one woman and six men on stage, and the bilingual group consists of three women and nine men.

"It may be because girls are not encouraged so much to express themselves," Schwab says. "In the States, improv groups always have fewer women than men. It's not that we don't want (female performers). Maybe it's also because guys feel they need to be heard and show off, and are less worried about speaking up and saying silly things."

Cai Yilin agrees.

"You need a really big heart to do this," says Cai, who works for a consulting firm in Beijing.

"I'm afraid girls who are very sentimental and fragile can't handle an audience being dead silent when their jokes are just not funny. The same goes for men.

"But once you are used to turning the unhappiness of daily life into something funny on stage, it really does make you a more positive, cheerful person."

In September the Beijing Comedy Center staged an all-women show featuring 12 stand-up comedians, including Cai and Pan.

"There aren't so many women comedians in Beijing, and we invited some from other places," Pan says. "We hoped it would make audiences realize that there is a rich diversity among female comedians with performing styles, and not just different looks and shapes."

Elken has started an all-women improv workshop, hoping more women will express themselves freely in the theatre.

"I just want to be equal in the world of entertainment. Maybe we cannot change the world, but at least we can change this small community. Comedy is my tool."

He Na and Yang Wanli contributed to the story.