|The Overeating and Obesity Cycle|
|Living - Health & Fitness|
|TS-Si News Service|
|Thursday, 30 September 2010 08:00|
Eugene, OR, USA. Obese individuals have fewer pleasure receptors and overeat to compensate, according to new research which provides evidence of the vicious cycle created when an obese individual overeats to compensate for reduced pleasure from food.
The study was led by Eric Stice, a University of Texas at Austin senior research fellow and a senior scientist at the Oregon Research Institute (ORI). Stice and his colleagues published their findings in The Journal of Neuroscience.
Stice has studied eating disorders and obesity for 20 years. This research has produced several prevention programs that reliably reduce risk for onset of eating disorders and obesity.
The research was conducted at the Robert and Beverly Lewis Center for NeuroImaging at the University of Oregon.
Weight Gain Is Associated with Reduced Striatal Response to Palatable Food. Eric Stice, Sonja Yokum, Kenneth Blum, and Cara Bohon. The Journal of Neuroscience 2010; 30(39): 13105-13109. doi:10.1523/JNEUROSCI.2105-10.2010
Consistent with the theory that individuals with hypofunctioning reward circuitry overeat to compensate for a reward deficit, obese versus lean humans have fewer striatal D2 receptors and show less striatal response to palatable food intake. Low striatal response to food intake predicts future weight gain in those at genetic risk for reduced signaling of dopamine-based reward circuitry. Yet animal studies indicate that intake of palatable food results in downregulation of D2 receptors, reduced D2 sensitivity, and decreased reward sensitivity, implying that overeating may contribute to reduced striatal responsivity. Thus, we tested whether overeating leads to reduced striatal responsivity to palatable food intake in humans using repeated-measures functional magnetic resonance imaging. Results indicated that women who gained weight over a 6 month period showed a reduction in striatal response to palatable food consumption relative to weight-stable women. Collectively, results suggest that low sensitivity of reward circuitry increases risk for overeating and that this overeating may further attenuate responsivity of reward circuitry in a feedforward process.
|Last Updated on Thursday, 30 September 2010 18:49|