Parental nagging won't shift teen weight

If you want to encourage your overweight or obese teenager to eat better and exercise more, nagging and verbal pressure won't work, research says.

In fact, badgering can lead some teens to develop a preoccupation with thoughts of eating and a distorted view of their body image.

Instead, parents need to talk less and do more, adopting healthy habits of their own.

In a 13-month study involving 100 teens, researchers from Western Australia and Poland found that overweight and obese adolescents with good role models reduced their BMI significantly over time.

Teenagers whose parents had poor habits stayed the same or put on weight.

"While we've long known that parental behaviour influences teenagers, this is the first study to show how parents' healthy eating and exercise directly impacts adolescent BMI," Curtin University Associate Professor Barbara Mullan says.

"Previous studies looked at self-esteem and body perceptions, but not actual weight.

"Approximately 21 per cent of teenagers who are overweight or obese return to a normal BMI over time and these findings suggest that a strong predictor may be parents who eat right and exercise."

Watching parents with good habits creates self-efficacy in teenagers—the belief that they have some control over their situation and thus the capacity to change, A/Prof Mullan says.

Teenage participants took part in three reporting periods, providing information on their physical condition, exercise and diet habits, perceptions of their bodies and sense of efficacy.

They also provided information on their parents' habits and ways in which their parents communicated about weight, diet and exercise.

What to do

"We were surprised that verbal pressure from parents had no effect on teenage behaviour, but in a way, it's not surprising, as young people at this stage are looking to show their autonomy," A/Prof Mullan says.

Teenagers also recognised a hint of adult hypocrisy.

"It does come down to 'do as I say, not as I do'," A/Prof Mullan says.

Given that obesity rates have doubled in teens over the past 30 years, the study stands to be vital for intervention and education programs.

However, a major challenge in translating its findings into healthier kids is the fact that parental behaviours are more engrained and harder to change.

A/Prof Mullan suggests creating competing habitual behaviours as an effective way to change, such as regularly going for a walk after dinner rather than having dessert.

Parents can also change their environment, including removing junk food from the house.

This article first appeared on ScienceNetwork Western Australia a science news website based at Scitech.