About The Buzz: Your Brain Knows How Many Calories are in Your Food?

WHAT THEY’RE SAYING

If you ask someone how many calories are in any given food, it’s likely that their guess won’t be very accurate. Their brain, however, has an implicit knowledge of calorie content that is more precise.

WHAT WE KNOW

More than one-third of US adults are obese (34.9% or 78.6 million) and approximately 17% (or 12.7 million) of children and adolescents aged 2—19 years are obese.^1-2 It is important for us to understand the factors that lead to being overweight and obese in order to decrease the chances of these rates climbing higher. The science behind food choices has demonstrated that when we are deciding what to eat, there is an intricate web of implicit and explicit awareness of a food’s true calorie content.

WHAT THE STUDIES SAY

In a recent study, researchers set out to understand the relationship between food choices and brain activity.³ They studied the ventromedial prefrontal cortex (vmPFC), which is the region of the brain known to encode the value of stimuli and predict immediate consumption. Researchers asked 29 healthy individuals to rate how many calories they thought were in each of 50 familiar food items. Then, while their brains were being scanned, participants were shown pictures of these food items and asked how much they were willing to pay for each item using an auction technique.

Results of this study demonstrated that although participants were poor at judging the calorie content of familiar foods, the true calorie content of these foods correlated with their willingness to pay and brain activity.

WHAT THIS MEANS

We are usually bad at judging how many calories are in foods, but because we’ve eaten similar foods in the past, our brain unconsciously processes calorie content. Different brain regions are engaged when we eat, which helps enable us to have a greater awareness of our food choices. We do not always respond by picking the best options, but this study demonstrates that there is an area of the brain that conceptualizes food calorie content.

OUR ADVICE

Certainly much more work needs to be done to understand how we make food choices and how information and other factors can alter those food choices. We do know, however, that because we are naturally poor at judging the caloric content of foods, we should always aim to fill half the plate with fruits and veggies at every meal and snack. Fruits and veggies are naturally low in calories and help you to maintain a healthy weight, an important factor in leading a healthy lifestyle.