Plus-Sized Flies Give Clues to Obesity (IMAGE) Cold Spring Harbor Laboratory Caption We still have lots to learn about causes and prevention of human obesity. For this reason, genetic researchers have created the first genetically induced model of obesity in the fruit fly. The plus-sized model, right, gains weight when its hormone regulating "fullness" is absent or fails to signal properly. These overweight flies, like genetically predisposed people, gain much more weight than those with no genetic predisposition when their diet is high in fattening foods. Credit Jen Beshel, Zhong Lab, CSHL Usage Restrictions please give credit License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.