Choosing what you eat is not simply a matter of taste. As you glance over a menu, your brain is making decisions based more on a food's calorific content, a study showed.
Earlier studies found that children and adults tend to choose high-calorie food.
"Our study sought to determine how people's awareness of calorific content influenced the brain areas known to be implicated in evaluating food options. We found that brain activity tracked the true calorific content of foods," said Alain Dagher, neurologist at the Montreal Neurological Institute and Hospital of McGill University.
The study 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 still centred on those foods with higher calorific content.
"Decisions about food consumption and calorific 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," Dagher added.
Understanding the reasons for people's food choices could help to control the factors that lead to obesity, the researchers concluded.
The study was published in the journal Psychological Science.