IMB Seminar: Alan Spector

Alan Spector
Department of Psychology
Florida State University

Gastric Bypass: Taste, Palatability, and Food Selection

Roux-en-Y gastric bypass (RYGB) has become a common bariatric surgical procedure because of its long-term effectiveness at promoting weight loss and curtailing type-2 diabetes mellitus. In addition to decreasing appetite and food intake, RYGB is currently thought to instigate changes in food preference and selection in a direction away from high fat and high sugar options based on changes in the relative palatability of these items. The support for this in humans is equivocal and largely derived from verbal report measures. In rodent models, there is evidence that RYGB leads to a progressive decline in the relative caloric intake of fat and an increase in the relative caloric intake of complex carbohydrates. Moreover, RYGB decreases the preference for sucrose and fat solutions in long-term two bottle tests (vs. water) in rats. However, the motivational potency of sugar and fat solutions, as assessed in a variety of short-term taste tests, appears to be relatively unaffected by the surgery. The observation that RYGB-induced changes in sugar and fat intake are often progressive suggests that experience is critical in this process. The working hypothesis of our group is that rats, and perhaps humans, are learning how to adjust their intake to minimize negative postingestive events. If such learned changes are unaccompanied by modulation in the palatability of the taste of the food then this process would be akin to conditioned avoidance. In contrast, if the palatability of the taste of the food reverses then a conditioned aversion process would be implicated. Understanding the behavioral properties of RYGB-induced changes in food selection should help facilitate efforts to identify the underlying physiological/neural mechanisms. This talk will review current findings in this context.


The talk will begin at 12:00pm. A pizza lunch will be served at 11:45am.