Did you forget what you had for lunch yesterday?  Or maybe you just forgot the details of that meeting you had this morning?  It might not be age that’s causing your memory loss, it might be your weight.

According to a recent study done by the Department of Psychology at Cambridge there has been a link discovered between high body mass index (BMI) and poor performance in episodic memory (as well as other brain functions like decision making, problems solving and emotions).  The study was published in The Quarterly Journal of Experimental Psychology and although it was a small study and the research is fairly new, researchers have found evidence between memory functions and obesity.

Episodic memory is your ability to recall past events.  Adults were tested in the study and those that were overweight scored significantly less than their slimmer peers.

Based on the results of the study, researchers believe that excess bodyweight just might be related to changes that occur to the structure and function of the brain.  These changes focus on the hippocampus, which is where we process memory and learning.  Links were also found between obesity and the frontal lobe, which is where we make decisions as well as process problem solving and emotions.

Although evidence between memory impairment and obesity is limited, researchers identified a measurable relationship.  What that means is they were able to see significant differences in the test results of obese participants and their more slender counterparts.

Although BMI isn’t the only indicator that should be used to determine overall health(since it is not a reliable indicator on its own), researchers tested 50 participants from age 18 to 35 with a body mass index (BMI) ranging from 18 to 51.  *NOTE – A BMI of 18-25 is considered by most to be a ‘healthy’ number, 25-30 being ‘overweight’ and anything over 30 is considered ‘obese’.  Participants were given a memory test called the ‘Treasure-Hunt Task’ where they were asked to hide items in complex scenes.  They were asked to remember which items they had hidden, where they had hidden them, and when they were hidden.

The results could suggest that changes to the brain’s structure and functional abilities may be accompanied with a reduced ability to create and process episodic memories.

An interesting note is the age range of the participants.  Even young adults (who were obese) were affected, which adds credibility to the relationship between BMI and ones ability to remember.

“We’re not saying that overweight people are necessarily more forgetful,” says researcher Dr. Cheke, “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.  In other words, it is possible that becoming overweight may make it harder to keep track of what and how much you have eaten, potentially making you more likely to overeat.”

The study was funded by the Medical Research Council and Girton College, University of Cambridge, and the James S McDonnell Foundation.