People struggling with obesity may gain less pleasure from eating
Findings from a study published in the October 17th issue of Science reveal that people struggling with obesity may receive less pleasure from eating, contributing to their weight. Eric Stice, psychology researcher at The University of Texas at Austin, and colleagues, found that individuals may have a predisposition to obesity due to their brain’s sluggish response to a sensation of fulfillment or pleasure from eating; these individuals compensate for the lack of reward from their brain by eating foods that are more calorie rich, this makes them gain weight. As Stice put it, “Obese people may have fewer dopamine receptors, so they overeat to compensate for this reward deficit… they need to take in more of a rewarding substance to experience the same level of pleasure as other people.” The following is an excerpt of an article from Medical News Today that discusses the study’s findings more:
For the study, Stice and colleagues used Functional Magnetic Resonance Imaging (fMRI) to watch activity in the dorsal striatum of female participants while they consumed a chocolate milkshake and then while they consumed a tasteless solution. They did this twice, once with 43 female students aged 18 to 22 and then also with 33 teenage girls aged 14 to 18.
They also tested both groups to find out which individuals had the Taq1A1 gene, which meant they had a lower number of dopamine D2 receptors.
Stice and colleagues then followed the participants for 12 months and monitored changes in their body mass index (BMI).
The results showed that participants whose striata were less active when they drank the milkshake and who also had the Taq1A1 gene were the ones most likely to put on weight over the follow up period.
Stice said understanding how the dopamine receptor deficit affects the brain’s reward circuits and their response to eating is important for the development of treatment options that could target this effect in people at higher risk of unhealthy weight gain.