Teen brains are no match for fast food TV ads

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How teens’ brains respond to TV advertisements for fast food can predict what they are going to eat for dinner, according to new research.

Teens who had greater responses in reward centers of the brain when viewing commercials for unhealthy foods—like cheeseburgers and milkshakes—from fast food restaurants ate more junk food in a simulated fast food restaurant.

Surprisingly, teens who had heightened brain responses associated with reward, memory, and visual attention to commercials for healthier foods—like salads and smoothies—from fast food restaurants were also prone to eat more junk food.

The findings contribute to previous studies about food advertising as a major contributor to obesity—and fast food restaurants are the main advertisers. But few studies have investigated the neural predictors of teens’ food intake.

“The ability of fast food commercials to prime these brain systems, potentially outside of the conscious awareness, may make it particularly challenging for adolescents to defend themselves against the negative effects of food marketing,” says lead author Ashley Gearhardt, associate professor of psychology at the University of Michigan.

“Teens are a major advertising target for the food industry and they receive little protection. Our results suggest that fast food restaurants adding more advertisements for healthier foods is unlikely to protect adolescents. Reducing the overall amount of food advertising viewed by teens is an important target for improving health.”

The study sample of 171 teens aged 13-16 viewed unhealthy fast food commercials with cheeseburgers and french fries; healthier commercials with salads, grilled chicken sandwiches; and nonfood commercials in a functional magnetic resonance imaging (FMRI). The participants could consume food featured in the commercials that varied in nutrition in a simulated fast food restaurant.

Some key findings:

  • More neural activation in the brain’s “reward” region predicted greater total food intake.
  • Healthier commercials from fast food restaurants are unlikely to encourage healthy food consumption. The restaurant logos and branding trigger cues associated with the sale of predominantly unhealthy foods.
  • Teens who showed less activation in a brain region associated with visual attention to unhealthy fast food commercials had more healthier food intake.

The study appears in the American Journal of Clinical Nutrition.

The study’s coauthors are from the Oregon Research Institute, the University of Connecticut, University at Buffalo, and the University of Michigan.

Source: University of Michigan