Researchers from the University of Buffalo have analyzed the motivation to eat and published their research in the October issue of Behavioral Neuroscience.

They that people with fewer dopamine receptors in the brain need to take more rewarding substances, like food and drugs, to have the same effect that other people get with less. Dopamine is a pleasure reward chemical made by the brain that helps making eating and other behaviors more satisfying.

Jennifer Temple, a research assistant professor of health sciences at The University of Buffalo, who conducted the study, said that these genes are also responsible for other compulsive behaviors, like alcoholism, drug abuse and others.

She and her team studied the DNA of 29 obese people and 45 overweight and at a healthy weight. Half of the participants had a form of the genes that made their brain with fewer dopamine receptors.
She arranged a laboratory experiment in which the subjects were encouraged to eat as much food as they liked, after they were performing some tasks on a computer. To receive more food the tasks got higher and higher in difficulty.

She observed that obese people who had the genotype with fewer dopamine receptors were twice more motivated then the other obese who had no such genotype. They worked harder even than normal weighted people who had the same
variation of genes.

She also concluded that people with normal weight might not be driven to food but too other rewarding regular activities, like physical activities, drinking alcohol, gambling and others.She stated that her team will continue the research on these issues.