The results of a recent study suggest that young adults who are overweight may have poorer episodic memory than their less stout counterparts. Published in The Quarterly Journal of Experimental Psychology, the preliminary study provides early evidence that higher body mass index (BMI) might be related to memory problems.
While the study was small, the results certainly require a closer look, supporting other evidence to suggest that excess body weight can alter the physical makeup of the brain (and thus how well it works). Of course, then, this can influence how well the brain performs specific cognitive tasks. More specifically, studies indicate that obesity has been linked with a particular dysfunction in the hippocampus—this is the part of the brain involved in memory and learning—and the frontal lobe—the part of the brain involved in emotions, problem solving, and decisions making.
Approximately 60 percent of adults in the United Kingdom are either overweight or obese. While that is alarming, experts predict the number will only increase—to to roughly 70 percent by the year 2034. Of course, obesity carries with it higher risks for other physical health problems including diabetes and heart disease, as well as physiological and psychological problems like anxiety and depression.
Dr. Lucy Cheke—of the Cambridge University Department of Psychology—explains, “Understanding what drives our consumption and how we instinctively regulate our eating behaviour is becoming more and more important given the rise of obesity in society. We know that to some extent hunger and satiety are driven by the balance of hormones in our bodies and brains, but psychological factors also play an important role.” For example, she describes how we tend to eat more when distracted by other things like television or working at the computer; and we might, sometimes, “comfort eat” when we are feeling down.
Thus, she goes on to say, “Increasingly, we’re beginning to see that memory – especially episodic memory, the kind where you mentally relive a past event – is also important. How vividly we remember a recent meal, for example today’s lunch, can make a difference to how hungry we feel and how much we are likely to reach out for that tasty chocolate bar later on.”
Finally, Cheke cautions, “We’re not saying that overweight people are necessarily more forgetful, but if these results are generalizable to memory in everyday life, then it could be that overweight people are less able to vividly relive details of past events – such as their past meals. Research on the role of memory in eating suggests that this might impair their ability to use memory to help regulate consumption.”