The prevalence of obesity in Australia is set to become significantly worse in the next 10 years, according to new modelling.
Researchers at the University of Sydney estimate by 2025 obesity among Australian adults will increase from 28 per cent to 35 per cent.
Even more concerning is that one in eight or 13 per cent will be severely obese - that is have a BMI of over 35.
The modelling calculated the amount of weight adults gain every year depending on their age, sex and current weight, as well as the BMI of adolescents as they enter adulthood.
According to the estimates, women will fare far worse with one in six predicted to be severely obese compared to one in 10 men.
Associate Professor Alison Hayes, who led the study published in the International Journal of Obesity, says the increase in obesity rates partly reflects natural progression because weight gain is cumulative and people already overweight are more likely to move into the obese category later in life.
"But if we could reduce average weight gain it wouldn't be as bad," she said.
Importantly, Ass Prof Hayes says the modelling highlights that contrary to popular belief it's young people who gain more weight each year than older people.
"An increase in childhood obesity means Australians are starting adulthood with a higher BMI and higher levels of obesity than ever before," said Ass Prof Hayes.
Making efforts now to decrease the weight gain of young people by about 10 per cent would have a much bigger effect on overall obesity rates in the future than decreasing the weight gain of older people, Hayes said.
In 1995 about one in 10 young adults were obese but in 2014 it was closer to one in five.
It's hoped the model can help accurately guide policy makers on what prevention strategies should be made a priority in order to reduce the burden of obesity on the health system.
"We know an increase in obesity and severe obesity will result in higher rates of chronic disease such as type 2 diabetes, cardiovascular disease and cancer," said Ass Prof Hayes.
