Taste, intake rate, and food choice in rats

The contribution of taste to the food choices of foraging rats was examined . Rats in a laboratory foraging paradigm searched for sequential opportunit ies to eat at two feeders containing chow-based food pellets that were plai n or flavored with saccharin or citric acid. Pellets cost the same number o f bar presses at both feeders. Saccharin adulteration had no effect on inta ke parameters. Citric-acid-flavored pellets were eaten more slowly and in s maller meals. If there was no alternative food, daily intake was slightly r educed. When the alternative food was plain, fewer meals and fewer pellets were taken of the citric-acid-flavored than plain pellets. When we graduall y increased the price of the plain pellets at one feeder, while the price a t the alternative feeder (which contained either plain or citric-acid-flavo red pellets) remained low the rate of eating (profitability) decreased at t he higher-price feeder, and the rats shifted their intake toward the less-c ostly, more profitable pellets. We compared the relationship between the re lative eating rate at each feeder and the relative meal size (or daily inta ke) at each feeder when the low-priced food was plain and when it was flavo red with citric acid, and found no differences. This indicates that taste m ay influence choice via its effect on rate of intake. (C) 2001 Elsevier Sci ence Inc. All rights reserved.