Neural response to fast food commercials in adolescents predicts intake.

BACKGROUND: Food advertising is a major contributor to obesity, and fast food (FF) restaurants are top advertisers. Research on the impact of food advertising in adolescents is lacking and no prior research has investigated neural predictors of food intake in adolescents. Neural systems implicated in reward could be key to understanding how food advertising drives food intake.

OBJECTIVES: To investigate how neural responses to both unhealthy and healthier FF commercials predict food intake in adolescents.

METHODS: A cross-sectional sample of 171 adolescents (aged 13-16 y) who ranged from normal weight to obese completed an fMRI paradigm where they viewed unhealthy and healthier FF and nonfood commercials. Adolescents then consumed a meal in a simulated FF restaurant where foods of varying nutritional profiles (unhealthy compared with healthier) were available.

RESULTS: Greater neural activation in reward-related regions (nucleus accumbens, r = 0.29; caudate nucleus, r = 0.27) to unhealthy FF commercials predicted greater total food intake. Greater responses to healthier FF relative to nonfood commercials in regions associated with reward (i.e., nucleus accumbens, r = 0.24), memory (i.e., hippocampus, r = 0.32), and sensorimotor processes (i.e., anterior cerebellum, r = 0.33) predicted greater total food and unhealthier food intake, but not healthier food intake. Lower activation in neural regions associated with visual attention and salience (e.g., precuneus, r = -0.35) to unhealthy relative to healthier FF commercials predicted healthier food intake.

CONCLUSIONS: These findings suggest that FF commercials contribute to overeating in adolescents through reward mechanisms. The addition of healthier commercials from FF restaurants is unlikely to encourage healthier food intake, but interventions that reduce the ability of unhealthy FF commercials to capture attention could be beneficial. However, an overall reduction in the amount of FF commercials exposure for adolescents is likely to be the most effective approach.