Obesity alters brain structure and function

Lucy Cheke and her colleagues at the University of Cambridge recently invited a few participants into her lab for a kind of ‘treasure hunt’.

The participants navigated a virtual environment on a computer screen, dropping off various objects along their way. They then answered a series of questions to test their memory of the task, such as where they had hidden a particular object.

When examining what might have influenced their performance, you might expect that Cheke would have been more concerned with the participant’s IQ – not their waistline. Yet she found a clear relationship between their Body Mass Index – a measure of your weight relative to your height – and apparent memory deficits: the higher a participant’s BMI, the worse they performed on the Treasure Hunt task.

In doing so, Cheke has contributed to a small but growing body of evidence showing that obesity is linked to brain shrinkage and memory deficits. This research suggests that obesity may contribute to the development of neurodegenerative conditions such as Alzheimer’s Disease.

Surprisingly, it also seems to show that the relationship between obesity and memory is a two-way street: being overweight or obese not only impacts on memory function, but may also affect future eating behaviour by altering our recollections of previous eating experiences.