The vicious cycle of overeating and obesity has apparently come under the limelight. A latest study undertaken by the University of Texas at Austin claims that obese individuals have fewer pleasure receptors and overeat to compensate. It was claimed that overeating weakens the responsiveness of pleasure receptors known as ‘hypofunctioning reward circuitry’ and declines the benefits achieved from overeating.
There seems to be a link between food intake and dopamine release. The degree of pleasure derived from eating appears to correlate with amount of dopamine released. It is assumed that obese individuals have lesser dopamine (D2) receptors in the brain as compared to thin individuals. It can therefore be presumed that obese individuals overeat to compensate for reward deficit. Scientists believe that individuals with fewer dopamine receptors require more intake of a rewarding substance like food or drug, so that they acquire similar effect obtained by lean people.
“Although recent findings suggested that obese individuals may experience less pleasure when eating, and therefore eat more to compensate, this is the first prospective evidence to show that the overeating itself further blunts the award circuitry. The weakened responsivity of the reward circuitry increases the risk for future weight gain in a feed-forward manner. This may explain why obesity typically shows a chronic course and is resistant to treatment,” enlightened Eric Stice a senior scientist at Oregon Research Institute.
Functional Magnetic Resonance Imaging (fMRI) was put to use for measuring the extent to which dorsal striatum an area of the brain gets activated in response to an individual’s consumption of chocolate milkshake than a tasteless solution. Alterations in body mass index of the participants were observed by experts for around six months. It was pointed out that participants who gained weight reported a considerably less activation in response to milkshake intake at the six month follow-up. The evaluation was conducted after comparing participant’s baseline scan and women who did not gain weight. The findings are seemingly beneficial for developing programs aimed to avoid and treat obesity.
The study was published in The Journal of Neuroscience.