The study presented below describes experiments that investigate the ability of insulin to inhibit food intake in awake, active marmots during the summer season. Our results suggest that increasing intraventricular insulin concentration during the summer active feeding period will cause a decrease in food intake and body weight of marmots. When infused with insulin into their lateral ventricles (Alzet #2002 minipumps), animals had significantly lower food intake as compared to their food intake during the control period. In addition, these animals lost body weight during the period of the insulin infusion. We suggest that during the summer when marmots are not hibernating and are actively feeding, brain insulin levels may play a role in regulating food intake.