FOOD IS A FEAST FOR YOUR EYES
By Rebecca Knight Monday, May 12, 2008
Does that slice of chocolate cake look delicious or is it all in your head?A report in the current issue of the journal Cell Metabolism highlights evidence of a gut hormone that causes people to eat more by making food appear more tasty.In a brain-imaging study, researchers from the Montreal Neurological Institute at McGill University found that reward centres respond more powerfully to pictures of food in people who had been given an infusion of the hormone known as ghrelin. The findings suggest that the two drives for feeding – metabolic signals and pleasure signals – are intertwined.
“When you go to the supermarket hungry, all food looks better,” said Alain Dagher, who led the study. “Your brain assigns a cost versus benefit to every food item. We've found that it is ghrelin that acts on the brain to make food more appealing.”This feeding behaviour may have once provided an adaptive advantage to humans. In our plentiful environment, however, it is a likely cause of obesity and its associated diseases.Ghrelin levels are known to increase before a meal and decrease afterwards, suggesting that it causes hunger and encourages eating. Treatments that disrupt the effects of ghrelin might help combat obesity.