Smell plays an important role in feeding behavior. Differences in the odor detection threshold (i.e., the lowest concentration of a substance detectable by the human olfactory sense) were found in a study that measured thresholds in 8 lean, fasted individuals before and during a 2-hour hyperinsulinemic-euglycemic insulin clamp.

Increased insulin led to reduced smelling capacity, potentially reducing the pleasantness of eating. Therefore, insulin action in the olfactory bulb may be involved in the process of satiety and may be of clinical interest as a possible factor in the pathogenesis of obesity.