Can neuroimaging explain the underlying mechanisms of overeating when comparing obese to lean subjects?
Summary
Obesity is a condition caused by overeating, to a state
were a person’s weight is not proportional to his or her
length anymore. The concept of overeating is not completely
solved. Many researchers have tried to unravel the underlying
mechanism that causes overeating using Positron Emission
Tomography (PET) or functional Magnetic Resonance
Imaging (fMRI).
Different research groups have used neuroimaging as a
tool to come up with a piece of the story and they tend to
agree that their answer is only part of the solution. Abnormal
activation of brain areas of an obese person in response
to eating is often in regions that are connected to
emotion, control of behavior and reward. Important areas
are the prefrontal cortex, dorsal insula, hippocampus, limbic/
paralimbic areas, amygdala and a reduced amount of
dopamine D2 receptors in the striatum. The role of hormones
is not taken into account in this paper, but is also
important for understanding overeating.
The real mechanism is complex and more studies have to
be done. Neuroimaging can be used to do further research.