Many epidemiological studies show that alcohol-derived calories added to food intake of men and women in amounts of 0-25% of total energy do not appreciably alter the average daily intake of other macronutrients (carbohydrate, fat, and protein). With such lack of evidence for caloric compensation, alcohol and its calories seem to make little contribution to metabolic energy, body weight, or body composition (as indicated by the body mass index, BMI). In fact, a major study by Colditz et al. (Am. J. Clin. Nutr. 54:49-55; 1991) reported a clear inverse relationship between alcohol intake and BMI for women! Research on alcohol metabolism has left unresolved some apparent contradictions regarding the effect of alcohol on caloric control, appetite and satiation, and body mass and composition. To resolve those apparent contradictions, the National Institute on Alcohol Abuse and Alcoholism cosponsored with the National Institute of Diabetes and Digestive and Kidney Diseases and the Beltsville Human Nutrition Research Center of the U.S. Department of Agriculture an all-day workshop titled "Alcohol and Calories: A Matter of Balance" on January 27, 1993. The workshop included sessions on calorimetry and body mass maintenance, alcohol metabolism, thermoregulation, and an overview of energy balance. This report provides summaries of the four discussion sessions at the workshop.