The impact of alcohol (ethanol) on resting energy expenditure of male non-obese volunteers was determined in two studies. In the first study the thermic effect of alcohol on resting metabolic rate (RMR) was assessed in ten male non-obese volunteers. In the second study the impact of alcohol on diet-induced thermogenesis (DTT) was determined in twelve male non-obese volunteers. Energy expenditure was measured with a ventilated-hood system. RMR was measured for 60 min with the subjects in a fasting state. In the first study subjects received in random order 20 g alcohol in concentrations of 75, 180 and 300 ml/l water respectively. After measurement of the RMR the thermic effect of alcohol was measured for 90 min. In the second study volunteers received in random order and in duplicate either a meal of food (2 M J ) plus an alcoholic aperitif (20 g alcohol in a 180 ml/l solution) or an isoenergetic meal of food alone (2.55 M J ) plus a placebo aperitif containing no alcohol. DIT was measured for 240 min. Alcohol induced a significant thermic effect, which varied between 0.22 and 0.30 kJ/min. No systematic difference in DIT was observed among the different concentrations. DIT was not significantly affected by the ingestion of alcohol. Total DIT was 219 (SE 14) kJ for the alcohol treatment and 185 (SE 20) k J for the control treatment. The results do not support the suggestion that alcohol is less efficiently used as an energy source in comparison with, for example, fats and carbohydrates. Alcohol: Resting metabolic rate: Diet-induced thermogenesisIn most Western countries total per capita alcohol consumption has increased dramatically over the last few decades (Sulkunen, 1976; World Health Organization, 1980). A recent nationwide food consumption study in The Netherlands showed that alcohol contributes on average 3 % to total daily energy intake in women and 5.4 YO in men aged 2 2 4 9 years (Ministerie van Welzijn, Volksgezondheid en Cultuur & Ministerie van Landbouw en Visserij, 1988). Similar values have been reported for men and women in other Western countries (Spring & Buss, 1977;Gruchow et al. 1985). The health effects of excessive alcohol intake are well documented (Klatsky, 1979;Mercy, 1980;Lieber, 1982), but the metabolic consequences and relation to the incidence of disease of moderate alcohol use remain to be definitely assessed. In this respect there is a general interest in the utilization of alcohol as an energy source. The issues that receive most attention are whether alcohol energy is added to or substituted for non-alcoholic energy in the diet, and whether energy intake from alcohol is related to increased levels of adiposity in the same way as energy intake from non-alcoholic sources.The majority of observational studies show that alcohol usually provides additional energy to the diet, but that its use is not associated with higher levels of adiposity (Bebb