Conditioned Flavor Preferences Based on Delayed Caloric Consequences

In four experiments we showed that rats prefer a flavor associated with a delayed edible consequence if the delayed consequence contains calories; the greater the number of calories, the greater the preference. We obtained conditioned preferences with delayed consequences of dextrose plus quinine, 8% polycose, 8% sucrose, 10 g of high fat mash, and 14 g of lab chow. No conditioned preferences were obtained with delayed consequences of saccharin, 10 g of low fat mash, 1% polycose, or 1% sucrose. Thus, it seems that flavor preferences based on delayed caloric consequences occur only if there are appreciable calories in the consequence.