According to the CDC in 2008, obesity is as high as 31.4 percent in some states and is a health care topic of concern. Using the Body Mass Index (BMI), obesity is a score of 30 or over. Besides health issues from excess weight, obese people are also at risk for heart disease, diabetes type 2 and certain types of cancer. The reason behind obesity has been highly questioned, with answers including genetics and environment. However, new research may explain why some people are obese — it is the wiring in the brain.
In the limbic system of the brain, the amygdala is responsible for our emotional and pleasurable responses. When you are hungry, your amygdala activates or “lights up.” After you finish eating, your amygdala “turns off.” However, in people who are obese, their amygdala does not shut off. Even if their stomach tells them that they are full, the amygdala will continue to send signals that food is still needed. For these people, food is a source of pleasure that their amygdala cannot get enough of. While this research is still in its early stages, it can describe why compulsive eaters continue to eat, even though they are full.
Other research studies have looked into the connection between pleasure and overeating. Dopamine, a neurotransmitter that is involved in pleasure, may also be involved with obesity. Research suggests that obese people have a lack of dopamine receptors and eating stimulates the receptors. PET scan images have shown that the higher the BMI is, the lower the amount of dopamine receptors. The effect that food has on the brains of over-eaters is similar to users of illicit drugs.
While obesity-brain research is still relatively new, it does provide a possibility to help people who overeat. According to the American Obesity Association, women have a higher increased prevalence of obesity compared to men: 50.8 percent to 28.8 percent in African-Americans, 40.1 percent to 29.4 percent in Mexican-Americans and 30.6 percent to 27.7 percent in whites. However, a gender difference in the obesity-brain link has not been determined yet.
-------------------------------------------------------------------------------------------------------------------------
Elizabeth Stannard Gromisch received her bachelor’s of science degree in neuroscience from Trinity College in Hartford, CT in May 2009. She is the Hartford Women's Health Examiner .