Overweight people ‘have brain deficits that affect self-control’

    14 July 2016

    A study in the journal Frontiers in Neuroscience suggests overweight people may have deficits in areas of the brain related to self-control and willpower.

    The study reported that overweight people had less white matter — a component of the brain that connects areas of grey matter — in the ‘salience network’, which researchers described as the ‘seat of motivation, willpower, and the ability to persevere through physical and emotional challenges’, and the dorsal striatum, which is involved in habitual behaviour.

    The suggestion is that overweight people may be neurologically predisposed to overeating and may behave more impulsively.

    It was also discovered that people with a higher body mass index had a similar amount of white matter and more grey matter overall.

    The researchers, from the University of Manitoba, took brain scans of 32 adults with no history of brain damage, addiction or mental illness. They also measured the subjects’ body mass index, and compared this information with differences in brain function and structure.

    Chase Figley, the study’s lead author, said: ‘It stands to reason that these changes could further affect the ability of overweight individuals to exert self-control and maintain healthy lifestyle choices. There are previous studies that imply elevated body fat can cause these sorts of brain changes.

    ‘It has been suggested that body composition itself might somehow affect the neural systems that underlie cognition, motivation, self-control and salience processing, which would in turn affect one’s ability to make better lifestyle choices, forgoing immediate and/or highly salient rewards for the sake of longer-term health and wellness goals.’

    Instant analysis
    The Telegraph describes this as ‘explosive’, which seems pretty generous for a study based on a grand total of 32 people and which offers some pretty limited conclusions. Essentially the study proposes a link between obesity and deficits in the areas of the brain responsible for things like self-control and motivation, but it offers only correlation, with no exploration of whether these deficits cause the obesity or vice versa. Presumably this will come later. At this stage it is difficult to think of any ways in which this information could be applied practically in order to improve the obesity problem.
    Research score: 2/5