Harnessing the rebellious streak among teenagers may help efforts to get youngsters to cut down on junk food, a study suggests.
Researchers in the United States reported that altering the way teenagers see adverts for fast food companies can lead to a change in dietary choices.
The study from researchers at Chicago Booth University and published in the journal Nature Human Behaviour, saw students given an "expose-style article" suggesting fast-food companies were trying to "hook consumers on addictive junk food for financial gain".
It found the teenage boys opted to make healthier daily dietary choices in the school's cafeteria, with researchers linking it to the pupil's desire to rebel.
Christopher Bryan, from the university, said: "Food marketing is deliberately designed to create positive emotional associations with junk food, to connect it with feelings of happiness and fun.
"What we've done is turn that around on the food marketers by exposing this manipulation to teenagers, triggering their natural strong aversion to being controlled by adults.
"If we could make more kids aware of that, it might make a real difference."
Boys involved in the study reduced their daily purchases of unhealthy drinks and snacks in the school cafeteria by 31 per cent in three months compared with the control group, the study said.
It added: "The study was less conclusive about the intervention's effect on teen girls' cafeteria purchases.
"Although, like boys, girls experienced a more negative immediate gut response to junk food after the expose intervention, their daily cafeteria purchases were similar whether they read the expose or the traditional health education material."
Australian Associated Press