Researchers discover why food always looks better when you are hungry

by Rich Bowden - May 7 2008, 01:31

A hormone found in the gut acts on the brain to make food look better, therefore making people eat more than is necessary, a new study has suggested.

Called ghrelin, the natural molecule causes the brain to find food more desirable when an individual is hungry say researchers.

"When you go to the supermarket hungry, every food looks better," said researcher Alain Dagher, a neurologist at McGill University in Montreal. "Now, we've found that it is ghrelin that acts on the brain to make food more appealing."

Researchers have found ghrelin levels to rise prior to eating and fall afterwards, suggesting it may have played an important role in our early development as a species, searching for food.

However they have found that in times when there is plentiful food, the hormone's interaction with the brain's reward centres may cause people to eat more than is necessary.

"Ghrelin has widespread effects," Dagher said. "It's not one or two brain regions, but the whole network. [After ghrelin infusion], food pictures become even more salient--people actually see them better. It influences not only visual processing, but also memory. People remembered the food pictures better when ghrelin was high."

Scientists studied twenty volunteers in the survey, twelve of whom had been injected with ghrelin while the others were administered a placebo.

Those who had been given ghrelin responded more strongly to pictures shown them of food and had a better memory of the picture.

The team's findings are published in this month's issue of Cell Metabolism, a publication of Cell Press.

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