Reward sensitivity increases food 'wanting' following television 'junk food' commercials

Obesity rates have been partly attributed to the easy access of cheap, high calorie food. However, many individuals exposed to the same food lie well within the healthy weight range. In her study, Dr. Natalie Loxton proposed reward sensitivity as a key trait predisposing some individuals to be highly attracted to cues linked with appetitive food -- such as a television commercial marketing junk food.

"We tested whether reward-sensitive individuals would experience greater pleasure and urge to eat after watching TV commercials featuring junk food, compared with those featuring healthy food or no food," Dr. Loxton said.

This independent study composed of 75 men and women who watched a 30 minute film embedded with junk food, healthy food, or no food featured in the commercials. Participants rated the pleasantness of food images and their desire to eat after watching the films.

"As hypothesised, reward sensitivity was associated with an increase in urge to eat in the junk food condition. There was no association in the healthy food condition and a reduced desire to eat in the no food condition," she said.

Dr. Loxton also discovered that reward sensitivity was associated with greater liking of junk food images, but only for women. There was no effect of reward sensitivity on liking of healthy food or non-food images.

Dr. Loxton confirmed that these findings support the role of greater food wanting in high reward sensitive individuals in response to appetitive food cues.