“It’s not my fault, it’s my brain!” may soon constitute a justified scientific argument to be used the next time your husband or your wife finds you with your head in the refrigerator in search of a little snack. According to the results of a recent study, feelings of fullness linked to food were less pronounced during the night than in the daytime. This may encourage us to overeat in an attempt to satisfy our needs. Why would night time snacking be ‘guided’ by our brains? Read on for the explanation.

The study was led by a team of researchers at Brigham Young University, and published by the scientific review Brain Imaging and Behavior, in March 2015. It showed that our brain activity changes depending on the time of day, at least for women. Travis D. Masterson, C. Brook Kirwan, Lance E. Davidson and James D. Le Cheminant studied the activity of certain areas of the brain using an MRI. Fifteen participants, all of them women, were shown a series of 360 food images, including both high and low energy foods. The images ranged from vegetables, cereals and fish, to cakes sweets and hamburgers. The test took place in two phases with at a one week interval: the first part was carried out from 6:30 am to 8:30 am and the second from 5:00pm to 7:00pm.

Subjectively, participants reported no difference in hunger at different times of the day, however they said that they were more preoccupied with thoughts of food in the evening. The MRI scans were able to provide an explanation. Firstly, neural responsiveness to visual food stimuli was more intense for high energy foods than the healthier low calorie option. Secondly, neural responsiveness in certain areas of the brain was less pronounced in the evening than in the morning, especially for high energy foods. Apparently, food (at least visually) produces feelings of satisfaction and fullness to a lesser extent in the evening than in the morning. This could encourage us to snack at night in an attempt to compensate and feel satiated.

Although this was just a preliminary study and further research is needed, particularly to establish a link between different neural reactions and our eating habits, the mystery of nighttime excursions to the refrigerator could soon be resolved.