University of Bristol graduate student Danielle Ferriday and her faculty advisor, Dr. Jeffrey Brunstrom, wanted to know if overweight and lean people responded differently to food cues, and, if they did, how the mind translates these different levels of desire-to-eat.

We all need to eat and we all encounter many food-related cues in our everyday lives, Ferriday told Reuters Health.

Ferriday enrolled 52 normal weight and 52 overweight women in the study, exposed them to the sight and smell of pizza and measured how much they salivated, as well as their psychological responses.

While lean participants didn't salivate much more once they saw and smelled the pizza, the overweight participants salivated about a third more than usual once the pizza showed up. They also had more desire to eat, measured by a standard scale, than the lean study subjects.

However, the overweight participants didn't eat more, even after being told to eat as much as they'd like.

What that means, say the researchers, is that the overweight don't necessarily eat more when at the table, but, because of their heightened sensitivity to the cues, they may be called to the table more often.

This is potentially important, because this sensitivity may encourage snacking and other bad eating habits that are associated with increased energy intake, overweight and weight gain, the investigators write in the July issue of the International Journal of Obesity.

The study couldn't answer why overweight people are more turned on by food. It is not clear, for example, whether they are born that way or do eating habits learned and developed over time cause a change?

While all the subjects in this study were women, we suspect that the findings would apply to men too, Ferriday noted.

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