According to the New Zealand Health Survey in 2016/17, about one in eight children aged 2 to 14 were obese (12 per cent). A further 21 per cent of children were overweight but not obese.
It is a worrying trend with the child obesity rate increasing from 8 per cent in 2006/07.
Obesity is more prevalent in the Maori and Pacific communities, with 18 per cent of Maori children and 29 per cent of Pacific children classed as obese.
The Whangarei woman wants a national regulation standard for health and fitness professionals to be introduced by the government.
Austin said in the open letter there were trainers who were not qualified adequately which could be the reason for increased injuries in the field and changes to qualifying standards might rectify it.
"This will lift the reputability of the qualified and educated health and fitness professionals who currently have to walk beside cowboys who have completed less than adequate, if any, qualifications to practice in an arena where we are dealing with the health and lives of other New Zealanders," she said.
"During 2017, the fitness sector became the most noted location for ACC claims, even more than rugby.
"A major factor contributing to this is the huge rise in fitness institutions which unfortunately hasn't been matched by an equal rise in satisfactorily qualified fitness professionals.
"We have a register of master builders whom we entrust with building our homes, so our house standards are nationally regulated by the government.
"But yet, we have hundreds of fitness professionals dealing with people's bodies and people's lives and potentially putting people at unknown risk and the industry is not regulated by government."
Austin has been working in the industry for 12 years after leaving the Waikato Institute of Technology with a bachelor of sport and exercise degree.
