Obesity and Cognition

What is the association between cognition and obesity?

Obesity is on the Rise

Currently around 60% of UK adults are overweight or obese: this number is predicted to rise to approximately 70% by 2034. Since obesity also increases the risk of physical (diabetes and heart disease) as well as psychological (depression and anxiety) health issues, these are worrying statistics.

Researchers and clinicians are increasingly recognising the obesity is more than a simple metabolic imbalance, but a complex syndrome that includes many psychological as well as physiological factors. 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.

Obesity and Memory

Research from our lab has found that overweight individuals may be less able to form and retrieve episodic memories. The research used a video game in which participants were required to hide items of food around a complex scene and then later remember what they had hidden, where and at what time. We found that people with a higher body mass index (BMI) were less accurate at remembering each one of these factors and in integrated them together into a single detailed event memory.

Why Does this Matter?

Memory is important for everyday life

Our memories of where we've been, what we've done and with whom are a central part of our personal identities. People with very severe memory impairments report experiencing "blankness" when thinking about their personal past. Of course, the very mild memory deficits we may be seeing in obesity are not of this scale. If our results are generalizable to memory in everyday life, this may mean that overweight individuals could experience memories slightly less vividly, and with slightly less contextual detail than they might otherwise have done. In otherwise healthy young adults, this may cause very few problems - perhaps people may struggle slightly more to remember which piece of juicy gossip came from which friend, or vividly relive an exciting moment - but these are minor problems. 

The issues may be more serious as people age.  Research suggests that the memory changes seen in obesity may interact with the changes that occur during normal aging, meaning that people who are overweight during middle age are more likely to struggle with memory problems in older age, and potentially to develop memory-related disorders such as dementia.

One Central aim of our research is to investigate the causes and mechanisms of memory changes in obesity throughout the lifespan, with the aim of discovering how these might be prevented, or even reversed.

Memory may help regulate consumption

It is already known that in obesity, many of the hormones controlling hunger such as leptin and ghrelin are dysregulated: people often find it difficult to properly detect whether they are truly hungry or full. What about the other factors controlling food intake? Could they also potentially be affected? A paper that came out this week suggests this may be the case.

If our results are generalizable, then overweight people might potentially be less able to remember their past meals; potentially impairing their ability to use memory to help regulate consumption. In other words, it is possible that the very fact of becoming overweight may make it harder to keep track of what and how much you have eaten, making you more likely to overeat.

A second central aim of our research is to investigate the potential "bi-directional" relationship between memory and obesity, and to develop interventions to reduce the impact of potential memory deficits on the regulation of consumption