Feeding patterns of rats chronically ingesting an ethanol-containing liquid diet.

We compared the feeding patterns of rats ingesting a 36% ethanol-containing liquid diet for 30 days with those of rats pair-fed an isocaloric liquid control diet or provided control diet or ground rat chow ad libitum. Ethanol-fed rats consumed fewer calories per day and gained less body weight than rats fed control diets ad libitum. Daily caloric intakes were approximately 50% lower during the first 10 days and 20% thereafter. Lower intakes in ethanol-fed rats occurred through a decrease in mean meal size rather than number of meals per day, although meals were more evenly distributed diurnally. Pair-fed rats ingested most of their food in one or two meals within a few hours of presentation. In a related experiment, a 4-hr duodenal infusion of ethanol at a rate comparable to that of ethanol ingestion resulted in plasma ethanol levels of 28 +/- 4 mM and suppressed 5-hr intake by approximately 40% by increasing the mean postmeal interval and satiety ratio. These results suggest that the suppressive effect of ethanol ingestion on food intake may be mediated in part by a post-gastric mechanism of ethanol action.