A high-fat meal or injection of lipids stimulates ethanol intake

Findings of earlier studies support the idea of a possible relation between dietary fat and ethanol intake, but it is unclear whether acute exposure to fat can increase ethanol consumption directly. In the current series of experiments, we examined whether daily overeating of fat, a single high-fat meal, or the injection of fat can increase ethanol intake. In Experiment 1, adult Sprague-Dawley rats were maintained on a high-fat diet (50% fat) for 7 days and switched subsequently to a laboratory chow diet while being trained to drink 9% ethanol. Rats that had eaten the greatest amount of the high-fat diet subsequently drank the most ethanol. In Experiment 2, a 1-h meal of the high-fat diet (50% fat) produced a significant increase in 7% ethanol consumption in comparison with what occurred after consumption of an equicaloric, low-fat (10% fat) meal. In Experiment 3, the orosensory effect of fat was eliminated with an intraperitoneal injection of a fat emulsion, Intralipid (20% fat, 5.0 ml). The injection of Intralipid, in comparison with saline, increased the ingestion of 9% ethanol. This finding is in contrast to what occurred with injection of an equicaloric, 50% glucose solution, which suppressed ethanol intake. These findings provide new evidence to support a positive relation between dietary fat and the consumption of ethanol.