Manicured children strut down the catwalk at a Beijing fashion show, one of thousands of events driving huge demand for child models in China that insiders warn leaves minors vulnerable to physical abuse, 12-hour-days and unrelenting pressure from pushy parents.

The kids' apparel market is growing faster than any other clothing sector in the country and was worth more than $40.5 billion in 2018 according to Euromonitor.

This combined with the rise of "kidfluencers" sponsored by brands to promote products on social media is spurring greater demand for young models — but experts warn of the heavy cost of pursuing such deals.

A video of a mother kicking her three-year-old daughter in fury at her failure to comply during a modelling job went viral earlier this year, causing outrage online.

Child models sometimes go through more than 100 outfit changes in a session, often working from morning till night.

But mental health experts warn it is not just physical exhaustion they have to contend with — there may be long term emotional implications.

"Children from the age of zero to six are mentally developing, they need a lot of exploration and freedom," explained child psychologist Gong Xueping.

"At work, the child model will deliberately show a lot of different expressions... but this is contrary to the child's own feelings of the moment. This limits the development of both emotional abilities and more complex psychological abilities for children, so I think it's a very bad choice," Gong added.

Competitors waiting to take the stage at a child model contest in Beijing. AFP

Hundreds of competitions

But there remains no shortage of parents interested in pushing their children into the profession.

Four-year-old twins Yumi and Yuki Xiao are not yet professional models but for nearly two years they have been taking classes where they are taught how to pose and pace the catwalk in the hopes that they can break into the industry.

Their parents invest in taking them around the country to compete in hundreds of national child modelling competitions.

"It's a lot of fun I like being on stage," insisted Yumi.

Children training at a modelling school. AFP

Like many other parents Xiao says he initially enrolled the two in child modelling to build their self confidence, but after Yumi and Yuki showed interest they started to invest more time and money into building a possible child modelling career path for them.

Lost childhoods

China's laws around child labour are complicated and parents of underage models are sometimes paid in secret to sidestep the red tape required to employ them.

Responding to the kicking video, Hangzhou authorities introduced regulations to limit the hours children work and ban children under 10 from being brand spokespeople.

A child model parading on the catwalk in front of judges. AFP

But many feel authorities are doing too little to protect kids from exploitation.

Thousands have debated the topic online, calling for rules to be tightened to prevent abuse.

"To me, child models are nothing different from child labour. They have to finish their work no matter how tired they are when other children are playing and their short childhoods are lost making money for their parents. I suggest that we step up legislation...to protect their rights and interests," one Weibo user said.

Agence France-Presse