A 2009 study by Jennifer L. Harris, John A. Bargh, and Kelly D. Brownell of Yale University published in Health Psychology and titled Priming Effects of Television Food Advertising on Eating Behavior poses some interesting questions about whether exposure to food advertising stimulates the appetite even when you are not hungry. The study sheds light on how exposure to food advertising may contribute to the obesity epidemic which both a U.S. Surgeon General and World Health Organization have labeled a leading cause of death, disease and disability. 
The study tested the hypothesis that exposure to food advertising during TV viewing contributed to obesity by triggering the urge to snack on available food.
The researchers studied two groups: elementary-school-age children and adults.
Children watched a cartoon that contained either food or non-food advertising and received a snack while watching.
Adults watched a TV program that included food advertising that promoted:
- Fun product benefits
- Nutrition benefits
They also measured a control group that saw no food advertising. The adults then tasted and evaluated a range of healthy to unhealthy snack foods in an apparently separate experiment.
For both children and adults, they measured the amount of snack foods consumed during and after exposure to the advertising.
They found that:
- Children consumed 45% more when exposed to food advertising.
- Adults consumed more of both healthy and unhealthy snack foods following exposure to snack food advertising compared to the control group.
They concluded, “In both groups, food advertising increased consumption of products not advertised. This effect was not related to reported hunger or other conscious influences.” They say that their experiments “demonstrate the power of food advertising to prime automatic eating behaviors and thus influence far more than brand preference alone.”
My take: People overeat for many reasons. This study shows the power of television to stimulate the appetite is one of them. However, it doesn’t address how much television contributes to overeating compared to other causes. That’s not criticism, just an observation about the study’s scope.
Speaking as someone who suffered serious health consequences from overeating and who recently shed 80 pounds, I found that my obesity was largely related to eating too many high-calorie meals at restaurants.
The meals were both over-portioned and high in fat. I began losing weight simply by becoming more aware of the caloric content of my foods through a 99-cent iPhone app. It helped me make healthier food choices. I also began vigorously exercising for an hour each day. I still watch just as much television as I always have.
I suspect that the priming effect discussed in this study is a contributing cause to obesity but not the main cause. Insofar as television influences food choice, we should also not forget that it can influence food choice in a positive direction. In my opinion, the largest factors contributing to obesity are lack of conscious thought about:
- How many calories we consume each day
- How poor food choices can negatively impact health.
All that food on television may look appetizing, but after $250,000 bypass surgery, believe me, a 99-cent iPhone app looks far more appealing.
