The recent finding that brain grey and white matter diminish with obesity is taken a little further with new MRI analysis finding that some subcortical brain mass is increased.
Interestingly, they are the subcortical brain structures that are involved in feeding behaviour. The obese people had larger left and right amygdalar volume, and their hippocampus was larger on the left. The greater the BMI, the larger the volume difference tended to be.
One suggestion is that the increased brain volume is associated with greater hedonic food memories, however this cannot be deduced from this research. It could be that those with larger volumes of these brain parts are more susceptible to the influences of a poor lifestyle. It is very interesting that the only areas found to be larger in obese people were those associated with feeding behaviour. Either way, it points clearly to a neurological component to the obesity epidemic and would suggest a reason why dietary programs which rely on prolonged compliance are so ineffective.
The psychological concept of ‘finite will’, where we have a finite capacity to resist temptation, suggests we lose resistance to desires over time and so obese people may lose their will more quickly due to a stronger ‘pull to eat’.
We have to wait for further study to indicate whether the brain volume difference is actually contributing to the obesity or is merely coincident.
