Australian Obesity Rate to Hit 35% by 2025

30 Sep 2016 --- New research from the University of Sydney, the Charles Perkins Centre and the George Institute for Global Health has predicted that obesity among Australian adults will reach 35 percent by 2025, up from its current 28 percent level. The prevalence of severe obesity is set to increase too, with 13 percent of adults expected to have a BMI of over 35 by 2025, figures up from five percent in 1995 and nine percent in 2014/15.

The new research, published in the International Journal of Obesity this week, used a model based on the most recent Australian data to conclude the new projections.

Today's figures show more Australians are overweight or obese than not, with around two-thirds of adults having a body mass index (BMI) greater than 25.

Lead researcher, Associate Professor Alison Hayes from the University’s School of Public Health, says the model is the first to predict weight gain among all Australian adults and to reflect changes in the proportion of overweight, obese and severely obese people over time.

“Contrary to popular belief, it is not in middle age that people suddenly pile on the pounds,” she explains. “In fact, at a population level, young people gain more weight each year than older people. But for most of us weight gain tends to be cumulative and so we’re more likely to move into an overweight or obese category later in life.”

The study also commented on the rising childhood obesity rates and their effect on the population’s waistlines as they grow into adulthood.

“An increase in childhood obesity means Australians are starting out adulthood with a higher BMI and higher levels of obesity than ever before,” Hayes says.

“For example, in 1995 around one in 10 young adults were obese, but in 2014 it was closer to one in five. We’re also living longer, and most sectors of the population gain weight throughout their life.”

“The model takes all this into account by calculating the amount of weight that adults put on every year depending on their age, sex and current weight, as well as the BMI of adolescents as they enter adulthood,” adds Hayes.

“It also takes into account the national birth rate, current life expectancy in Australia and higher mortality of people with high BMI.”

The model reveals that targets set by The World Health Organization (WHO) to maintain the 2010 levels of overweight and obesity will not be met in Australia.

“We compared model predictions of obesity and severe obesity starting in 1995 all the way to 2014, and they were consistent with what actually happened,” Professor Hayes says.

“This means we can be very confident about the predictions into the future.”

Despite the unattractive outlook portrayed by the model, researchers claim it can be used to guide intervention policy by allowing researchers to pose different scenarios and see the impact on projections. For example, ‘What happens if weight gain in young adults is reduced by 10 percent?’ or ‘What if we reduce childhood obesity?’

“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, with an increased strain on the health system and healthcare costs,” Hayes explains.

“Any reduction in the incidence of obesity going forward will have beneficial impacts on population health and the healthcare costs, but the model can help establish where our efforts should be prioritized.”

“The next phase of our research will examine the evidence for successful prevention or weight loss programs and use the model to help us work out the most effective – and cost-effective – ways to manage obesity in the future,” she concludes.