(Medical Xpress) -- A University of Queensland study has found that while obesity rates have been partly attributed to the easy access of cheap, high calorie food, many individuals exposed to the same food continue to lie well within the healthy weight range.
UQ School of Psychology lecturer Dr Natalie Loxton and UQ student Samantha Byrne explored the personality traits that make some people more vulnerable to over-eating and weight gain.
The study examined why some people are affected more than others by the same TV commercials when it comes to an advertisement featuring the latest mouth-watering hamburger.
Dr Loxton travelled to Zurich last month to present these findings at the annual conference of the Society for the Study of Ingestive Behavior (SSIB), the foremost society for research into all aspects of eating and drinking behavior.
The paper, Reward sensitivity increases food wanting following television junk food commercials, proposes 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 comprised 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 film.
As hypothesised, reward sensitivity was associated with an increase in urge to eat in the junk food condition," Dr Loxton said.
There was no association in the healthy food condition and a reduced desire to eat in the no food condition.
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 supported the role of greater food wanting in high reward sensitive individuals in response to appetitive food cues.