Do you always end up snacking on that bag of chips instead of going for a piece of fruit every time you open the pantry? The same memory system that allowed our hunter-gatherer ancestors to effectively locate high-energy resources might be causing this eating behavior. 

A study recently published in Nature’s Scientific Reports tested people’s ability to remember the location of various food items in an experimental maze. The 512 participants followed a path, coming across various high- and low-calorie foods, such as chocolate brownies and apples, respectively, or the equivalent food odors presented in scented cotton pads. The participants were divided into two groups: while the first got to see, taste, and smell actual food products, the second one was only allowed to smell food-odor samples. At each station the individuals rated how familiarized they were with that food and how much they liked and desired to eat it. After navigating the maze, the participants were asked to recall the location of each food or odor on a map of the room.

The participants in the first group were better at remembering the location of high-calorie foods than of low-calorie ones, regardless of how much they said to like, desire, or be familiar with the food items. The participants in group 2 best recalled the location of the cotton pads scented with calorie-dense foods. 

Maze of bushes in botanical park - Ayia Napa Cyprus - nature background
Study participants were asked to navigate a maze containing either high or low-calorie foods, or cotton pads scented with those same foods. The participants best remembered the location of calorie-dense foods or their corresponding scents.

According to the authors, the brains of our foraging ancestors probably evolved so that their memories would prioritize the location of calorie-rich foods, allowing them to avoid starvation in environments where food availability was constantly changing. A well-developed sense of smell is also thought to have helped them survive. It seems that the human brain can use odor cues to deduce the caloric properties of foods, which, in the past, might have helped our ancestral hunters locate and remember the placement of foods that provided them with more energy. In that sense, it is no surprise that the participants of the study were better at mapping the odors of high-calorie foods to the appropriate locations of the maze. Still, it seems that combining smell with other senses, such as sight and taste, allowed the participants to remember the location of food products better. 

But what was once a blessing, might now be a curse. Although we need more studies to clarify the effect that this preference of memory towards calorie-rich foods has on actual eating behavior, these findings might explain our relationship with food in the modern world. These preserved brain mechanisms might be the reason why high-calorie foods seem easier to obtain and why we often find ourselves on the way to fast-food restaurants. However, some people’s brains might specifically remember the location of calorie-dense foods better than others. These individual differences might explain why some people are more often drawn to foods with high caloric content, making them more prone to gain weight

The bottom line is that your memory might actually be playing tricks on you. But you know what they say… out of sight, out of mind. It might help to start removing the unhealthy snacks you have in your kitchen. And if you want to eat healthier, you can also take a look at these daily activities to eat well all year-long.