People with an unhealthy BMI are less in touch with their emotions, study shows

People who are obese or underweight are less in touch with their emotions than those at a healthy weight, London academics claimed today.

Research by Brunel University and Imperial College found an association between extreme body mass index (BMI) and the capacity to understand and handle feelings.

They compared BMI scores and psychometric tests performed over a 15-year period on people aged 31 and 46 and found that those whose weight changed most, either increasing or falling, were most likely to have alexithymia. This is defined as a difficulty identifying and expressing emotions, and is said to affect one in 10 adult Europeans.

Obesity and anorexia have previously been associated with alexithymia. Today’s study, involving more than 3,200 Finnish people and published online in PLOS One, is the first to apparently confirm that people with extreme weight problems are less able to process emotions.

Alexithymia is a key factor in autism, which shares several genetic causes with obesity . Depression also has been linked to alexithymia and obesity.

Professor Alex Blakemore, of Brunel, said: “There might be something about being overweight that blunts people’s ability to identify and discuss their own emotions. Perhaps the overwhelming social stigma or, as our study suggests, a higher level of depression.

“Another possibility is that whatever affects the brain to cause alexithymia also affects the brain signals that control eating which might explain why it is associated with both anorexia and obesity.”

It is not known what causes the link between BMI and alexithymia. Some people eat in response to emotions, without understanding the underlying trigger.

Professor Blakemore said weight management programmes should offer emotional support.

She added: “The good news is that our ability to understand and discuss our emotions is not fixed — it can change over time — something to consider when looking at ways to move towards a healthy weight.