Food intake reduction: Satiation or aversion?

Intraperitoneal injections of a wide range of doses of lithium chloride (LiCl) were given to two groups of Long—Evans rats. In the first group, the effect of the drug on the eating behavior of the animals was measured. In the second group, we tested whether the rats had learned a taste aversion to flavored fluids that had been paired with the LiCl injections. The administration of doses of LiCl that produced reductions in eating in the order of 50% (P < 0.05) did not produce learned taste aversion. These results indicate that a decrease in food intake is a more sensitive test of malaise than the learning of a taste aversion. Therefore, the taste aversion test to rule out malaise as a possible explanation of reductions in eating in satiation research should be used with reservations.