She called for regulations to protect models before New Zealand industry expectations reached European levels.
"I hope those girls get to a stage where they don't feel like they have to live that kind of lifestyle and they realise living like that is not conducive to happiness," she said.
"You are supposed to look a certain way, despite what people say, and if you don't fit into the clothes or if you're the biggest girl there, that's a horrible feeling.
"There might be food backstage and a girl might say, 'I've already eaten muesli today' and you'll be like, 'well it's 4 o'clock in the afternoon, that's a little bit weird'."
Other models said the industry's demands were often exploitative and unrealistic.
"Before I started [modelling] I never thought my legs were big, but you start realising all these little problems," said one. "Knowing that there's always something to improve is hard to deal with."
But another girl said her agency told her that if she ate healthily and exercised she would be able to book more, better-paying jobs.
"Agencies don't tell you to be skinny or stop eating - they tell you to get off your ass and go for a run."
Metro Consultancy dietitian Amy Liu said many crash diets had potentially dangerous side-effects.
"Models who follow any type of starvation diet can be left weak, dizzy and undernourished," she said. "They're definitely high risk."