Studies in both humans and animals suggest a positive relationship between the intake of ethanol and intake of fat, which may contribute to alcohol abuse. This relationship may be mediated, in part, by hypothalamic orexigenic peptides such as orexin (OX), which stimulate both consumption of ethanol and fat, and circulating triglycerides (TG), which stimulate these peptides and promote consummatory behavior. The present study investigated this vicious cycle between ethanol and fat, to further characterize its relation to TG and to test the effects of lowering TG levels. In Experiment 1, the behavioral relationship between fat intake and ethanol was confirmed. Adult male Sprague-Dawley rats, chronically injected with ethanol (1 g/kg i.p.) and tested in terms of their preference for a high-fat compared to low-fat diet, showed a significant increase in their fat preference, compared to rats injected with saline, in measures of 2 h and 24 h intake. Experiment 2 tested the relationship of circulating TG in this positive association between ethanol and fat, in rats chronically consuming 9% ethanol vs. water and given acute meal tests (25 kcal) of a high-fat vs. low-fat diet. Levels of TG were elevated in response to both chronic drinking of ethanol vs. water and acute eating of a high-fat vs. low-fat meal. Most importantly, ethanol and a high-fat diet showed an interaction effect, whereby their combination produced a considerably larger increase in TG levels (+172%) compared to ethanol with a low-fat diet (+111%). In Experiment 3, a direct manipulation of TG levels was found to affect ethanol intake. After administration of gemfibrozil (50 mg/kg i.g.) compared to vehicle, TG levels were lowered by 37%, and ethanol intake was significantly reduced. In Experiment 4, the TG-lowering drug gemfibrozil also caused a significant reduction in the expression of the orexigenic peptide OX, in the perifornical lateral hypothalamus. These results support the existence of a vicious cycle between ethanol and fat whereby each nutrient stimulates intake of the other. Within this vicious cycle, ethanol and fat act synergistically to increase TG levels, which in turn stimulate peptides that promote further consumption, and these phenomena are reversed by gemfibrozil, which lowers TG levels.