A new study has found that brains of obese teenagers are unusually susceptible to food commercials.
Dartmouth study show that TV food commercials disproportionately stimulate the brains of overweight teens, including the regions that control pleasure, taste and, most surprisingly, the mouth, suggesting they mentally simulate unhealthy eating habits.
The findings suggest such habits may make it difficult to lose weight later in life, and that dieting efforts should not only target the initial desire to eat tempting food, but the subsequent thinking about actually tasting and eating it, in other words, one should picture himself munching a salad rather than a cheeseburger.
The results show that in all the adolescents, the brain regions involved in attention and focus (occipital lobe, precuneus, superior temporal gyri and right insula) and in processing rewards (nucleus accumbens and orbitofrontal cortex) were more strongly active while viewing food commercials than non-food commercials.
Also, adolescents with higher body fat showed greater reward-related activity than healthy weight teens in the orbitofrontal cortex and in regions associated with taste perception. The most surprising finding was that the food commercials also activated the overweight adolescents' brain region that controls their mouths. This region is part of the larger sensory system that is important for observational learning.
Lead author Kristina Rapuano said that this finding suggests the intriguing possibility that overweight adolescents mentally simulate eating while watching food commercials, adding that these brain responses may demonstrate one factor whereby unhealthy eating behaviors become reinforced and turned into habits that potentially hamper a person's ability lose weight later in life.
The study is published in the journal Cerebral Cortex.