Scientists in a new study have discovered why does our brain makes us go for junk food over healthy meals.
According to the scientists from the Montreal Neurological Institute and Hospital of McGill University and the McGill University Health Centre, choosing what a person eats wasn't just simply a matter of taste. When a person glances over a menu or peruses the shelves in a supermarket, their brain makes decisions based more on a food's caloric content.
The study which is based on brain scans of healthy participants who were asked to examine pictures of various foods. Participants rated which foods they would like to consume and were asked to estimate the calorie content of each food. Surprisingly, they were poor at accurately judging the number of calories in the various foods, but their choices and their willingness to pay still centered on those foods with higher caloric content.
Lead author of the study, Dr. Alain Dagher, said that their study sought to determine how people's awareness of caloric content influenced the brain areas known to be implicated in evaluating food options. They found that brain activity tracked the true caloric content of foods.
Decisions about food consumption and caloric density are linked to a part of the brain called the ventromedial prefrontal cortex, an area that encodes the value of stimuli and predicts immediate consumption.
Understanding the reasons for people's food choices could help to control the factors that lead to obesity, which is linked to many health problems including high blood pressure, heart disease and type 2 diabetes.
The study is published in Psychological Science.