Extra pounds can harm your memory
Overweight young adults have a harder time to recall past events, according to a study from the University of Cambridge.
Researchers from the Department of Psychology at Cambridge found an association between high body mass index (BMI) and poorer performance on a test of episodic memory.
The researchers tested 50 participants aged 18-35, with body mass indexes (BMIs) ranging from 18 through to 51 — a BMI of 18-25 is considered healthy, 25-30 overweight, and over 30 obese. The participants took part in a memory test known as the ‘Treasure-Hunt Task’, where they were asked to hide items around complex scenes (for example, a desert with palm trees) across two ‘days’. They were then asked to remember which items they had hidden, where they had hidden them, and when they were hidden. Overall, the team found an association between higher BMI and poorer performance on the tasks.
This was a small, preliminary study and so the researchers caution that further research will be necessary to establish whether the results of this study can be generalised to overweight individuals in general, and to episodic memory in everyday life rather than in experimental conditions.
“We’re not saying that overweight people are necessarily more forgetful,” cautions 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.”
Dr Cheke believes that this work is an important step in understanding the role of psychological factors in obesity. “The possibility that there may be episodic memory deficits in overweight individuals is of concern, especially given the growing evidence that episodic memory may have a considerable influence on feeding behaviour and appetite regulation,” she says.
Co-author Dr Jon Simons adds: “By recognising and addressing these psychological factors head-on, not only can we come to understand obesity better, but we may enable the creation of interventions that can make a real difference to health and wellbeing.”
The study was funded by the Medical Research Council and Girton College, University of Cambridge, and the James S McDonnell Foundation.
