Young adults tip scales wrong way

The 10-year study by the Murdoch Childrens Research Institute tracked the weight of more than 1500 Victorian adolescents from the age of 14 to 24 years. It found weight gain accelerated in the years after leaving school, with obesity rates doubling and the proportion of those classified as overweight increasing by two thirds.

Young men were particularly at risk, with the rate of overweight males more than doubling from 18 per cent during the teen years to 39 per cent by the age of 24.

Lead researcher Professor George Patton said weight gain in the post-school years could be attributed to negative lifestyle habits, which often started in adolescence.

"Adolescence is a time of tremendous physical and emotional changes where lifestyles change and risks arising from a drop-off in exercise and a rise in poor eating are carried forward, affecting future patterns of weight gain and obesity," Professor Patton said.

"With the obesity epidemic, we have seen a big focus on younger children but we may be missing a real opportunity to take action during adolescence to prevent weight gain in young adults."

The study, published online by the Journal of Adolescent Health, is the first of its kind to look at the shift in weight between adolescence and young adulthood. The proportion of overweight participants increased from 20 per cent in mid-adolescence to 33 per cent at the age of 24. Obesity rose from 3.6 per cent to 6.7 per cent.

Obese teenagers were unlikely to shift the weight in later years, with 60 per cent still obese and none returning to a normal weight in their 20s. On a more positive note, adolescents who were overweight for less than twelve months had mostly managed to get back to a normal weight by their early 20s. Females who became overweight as teenagers fared better than males.

During the teen years, 22 per cent of girls were overweight compared with 18 per cent of boys. However, weight gain became a bigger problem among young men in their 20s, with the proportion of overweight males increasing to 39 per cent by the age of 24, compared with 27 per cent of females.

"Females are more likely to perceive themselves as being overweight at normal weights. In contrast overweight males are more likely to see themselves as at a normal weight," Professor Patton said.

"These differences lead to females being more likely than males to take measures to control their weight and may explain the gender differences in weight gain."