High-calorie foods were vital for providing energy to our hunter-gatherer ancestors, potentially even fuelling modern human brain development.
Although the world was vastly different then, a new study published in the journal Science Advances demonstrates how an inherent survival-driven preference for these foods may still be hardwired into our brains.
In an eloquently designed experiment, scientists from The Netherlands showed that people are better at remembering the location of high-calorie foods regardless of their food preferences or familiarity.
They did this by putting more than 500 people through a “maze” dotted with foods they were directed to eat or food odours on cotton swabs they had to smell. The samples consisted of high- and low-calorie items such as apples, chocolate, tomatoes and chips.
When tasting and smelling each food, the volunteers answered questions about it, including how much they liked it or how familiar it was.
Then they were taken backstage for a surprise assignment, where they were asked to show the correct location of each food on a map of the food maze.
Given participants were not informed of this spatial memory task, their preferential ability to locate high-calorie items is striking – and could influence how we navigate our modern food settings, according to first author Rachelle Vries from Wageningen University and Research.
“We have reason to suspect that the high-calorie spatial memory bias could stimulate people to choose for eating high-calorie foods, by making high-calorie options seem relatively easier or more convenient to find,” she says.
“For instance, it may lead us to choose more often for chips, instead of tomatoes, in a supermarket, or visit fast-food outlets more frequently.”
This could exacerbate the problems generated by our modern consumption-driven food environment teeming with highly processed, high-calorie foods that are associated with obesity, heart disease and mortality.
Indeed, the study coincides with more research linking food marketing to higher rates of obesity, published in JAMA Network Open.
“A key mechanism by which food and beverage marketing increases obesity risk is by changing consumer preferences, which are highly malleable,” write Sara Bleich, from the Harvard TH Chan School of Public Health, US, and co-authors.
Across 370 counties in 44 US states, this group found that increased media restaurant advertising corresponded with a modest weight gain in low-, but not high-income communities. They suggest this could be explained by unhealthier foods targeted at the former market.
The study aligns with other research showing that unhealthy food and drink marketing commonly targets poorer and low minority populations, prompting the authors to call for further attention to this issue.
“Efforts to decrease restaurant advertising in low-income communities should be intensified and rigorously evaluated to understand their potential for increasing health equity.”
Natalie Parletta is a freelance science writer based in Adelaide and an adjunct senior research fellow with the University of South Australia.
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