Why Did Obese Individuals Tend To Eat More?

Modern lifestyle and unhealthy diet have made obesity to fast becoming an epidemic that worries many health professionals. This is because obesity will eventually lead to many undesired medical disorders like heart disease, diabetes, hypertension (high blood pressure), and even certain types of cancer.

Meanwhile, it seems that obese individuals tend to take in more food to the contrary that they are supposed to eat less to cut down their weight. Such phenomenon has aroused the curiosity of scientists and prompted them to find out the cause behind that.

Researchers from the University of Texas (UT), the Oregon Research Institute, and the Yale University School of Medicine, Connecticut, jointly found that obese persons may have fewer pleasure receptors in their brains, which require them to feed themselves with more of a rewarding substance like food or drugs so that they could experience the same level of pleasure as other people.

The findings of the study, which is one of the first to positively identify factors that increase people's weight gain risk in the future, were published in the month of October 2008 in the journal Science.

According to the researchers, human brain releases the so-called pleasure chemical dopamine, which is believed to be a reward to the body for consuming life-sustaining nutrition. They suspected weak reward centers in the brain prompt obese people to eat more, and they believed obese people might have fewer dopamine receptors causing them to overeat so as to compensate for this reward deficit.

A technique known as functional Magnetic Resonance Imaging (fMRI) was used to examine the extent to which pleasure receptors in individuals were activated in response to a taste of chocolate milkshake versus tasteless solution. The participants were then tested for the presence of a genetic variation that was linked to a lower number of the dopamine receptors. Changes in the participants’ BMI (body mass index) were tracked over a one-year period.

The researchers believed the results from the study are key for understanding weight gain and to helping at-risk obese individuals. By identifying changes in behavior or pharmacological options, it is hoped that the reward deficit could be corrected to prevent and treat obesity.