New study finds that a simple and brief intervention can provide lasting protection for teenagers against these harmful effects of junk food marketing. The findings of the study are published in the Nature Human Behaviour.
One of the biggest obstacles is the enormous volume of food marketing kids are exposed to every day. That marketing is designed to foster strong positive associations with junk food in kids' minds and to drive overeating and research has shown that it works.
In the study, "A Values-Alignment Intervention Protects Adolescents from the Effects of Food Marketing," Booth's Christopher J. Bryan, University of Texas at Austin's David S. Yeager, and Booth PhD candidate Cintia P. Hinojosa find that reframing how students view food-marketing campaigns can spur adolescents, particularly boys, to make healthier daily dietary choices for an extended period of time.
A preliminary study took place among eighth graders at a Texas middle school in 2016. The researchers went into classrooms and had one group of students read a fact-based, expos-style article on big food companies. The article framed the corporations as manipulative marketers trying to hook consumers on addictive junk food for financial gain. The stories also described deceptive product labels and advertising practices that target vulnerable populations, including very young children and the poor.
A separate, control group of students received traditional material from existing health education programs about the benefits of healthy eating. The researchers found that the group that read the exposs chose fewer junk food snacks and selected water over sugary sodas the next day.
In the new study, released today, teens first read the marketing expos material and then did an activity called "Make It True," meant to reinforce the negative portrayal of food marketing. The students received images of food advertisements on iPads with instructions to write or draw on the ads graffiti style to transform the ads from false to true.
The latest study, which used a new sample of eighth graders, found that the effects of the marketing expos intervention endured for the remainder of the school year a full three months. The effects were particularly impressive among boys, who reduced their daily purchases of unhealthy drinks and snacks in the school cafeteria by 31 percent in that time period, compared with the control group.
Appealing to teenagers' natural impulse to "stick it to the man" and their developmentally heightened sense of fairness may finally provide a way for the public-health community to compete against dramatically-better-funded junk food marketers. This brief, inexpensive, and easily scalable intervention appears to provide lasting protection against the enticing power of junk food marketing and to change eating habits for the better.
"Most past interventions seemed to assume that alerting teenagers to the negative long-term health consequences of bad diets would be an effective way to motivate them to change their behavior," said Bryan.
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 expos intervention, their daily cafeteria purchases were similar whether they read the expos or the traditional health education material.
What is unclear is whether the similar purchases meant that neither intervention improved girls' dietary choices or that both were effective in girls, but for different reasons. The researchers suspect that, while traditional health education is completely ineffective at changing boys' behavior, it might influence girls' choices because it mentions calories, which might trigger social pressure to be thin. If that is the case, it suggests the expos might be a preferable option for girls too because it achieves similar results with less risk of body shaming.