Westerners may be genetically programmed to eat more fatty foods and drink more alcohol than those in the east, researchers claimed today.
Scientists at the University of Aberdeen said people in Europe could have evolved to make them more likely to opt for high-fat food and alcohol than those in Asia.
They found a genetic "switch" - a piece of DNA which turns genes on or off within cells - which controls the galanin gene.
The gene is switched on in the part of the brain called the hypothalamus and regulates appetite and thirst.
The study discovered that the switch was weaker in Asian people compared to Europeans.
The researchers said historically people who ate fatty food and drank alcohol were more likely to survive long, cold winters, as they provided important sources of calories.
Doctor Alasdair MacKenzie, who led the research, said: "The switch controls the areas of the brain which allows us to select which foods we would like to eat and if it is turned on too strongly we are more likely to crave fatty foods and alcohol.
"The fact that the weaker switch is found more frequently in Asians compared to Europeans suggests they are less inclined to select such options.
"Thus, a preference for food with a higher fat and alcohol content would have been important for survival. The negative effects of fat and alcohol we see today would not have mattered so much then as life expectancies were between 30 and 40 years.
"It is possible that during the winter individuals with the weaker switch may not have survived as well in Europe as those with the stronger switch and as a result those in the west have evolved to favour a high fat and alcohol-rich diet."
The study was published in the Journal of Neuropsychopharmocology.