Overweight people have worse memories for times, places and specific emotions they have experienced, a new study finds.
The higher people’s BMI, researchers found, the worse their episodic memory.
Episodic memory is the collection of memories that occurred at a particular moment in time.
It is often contrasted with semantic memory, which is our general knowledge about the world.
The study adds further evidence for the cognitive disadvantages of being overweight.
Dr Lucy Cheke, who led the study, said:
“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 — we tend to eat more when distracted by television or working, and perhaps to ‘comfort eat’ when we are sad, for example.
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.”
The study tested 50 people with a range of BMIs from 18 to 51.
The normal range for BMI is 18-25, 25-30 is considered overweight and over 30 is obese.
Researchers found that the higher people’s BMI, the worse they performed on a memory task.
Dr Cheke said:
“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.
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 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.”
Dr Jon Simons, who co-authored the study, said:
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 published in The Quarterly Journal of Experimental Psychology (Cheke et al., 2016).
Brain image from Shutterstock