There are implications in the literature that wine is different from other alcoholic beverages and that it may even have a beneficial effect on the nutritional process. A metabolic study was undertaken in an attempt to document the effects of wine versus ethanol on absorption of various nutrients. Nitrogen and caloric data are presented here. During each of four 18-day experimental periods, six healthy, young men were given, in random order, a liter per day of the following test beverages: Zinfandel wine (9.3% w/v alcohol); dealcoholized Zinfandel wine; pure ethanol (9.3% w/v aqueous alcohol solution); and deionized water. These beverages were divided into four equal feedings and administered with a carefully controlled isocaloric diet over a 12-hr period. The subjects tended to lose weight on alcohol-containing regimens, suggesting that calories from alcohol may not be as efficient as those from fat and carbohydrate. Urinary excretion of nitrogen was significantly greater during wine and ethanol administration than during feeding of the other test beverages. This was reflected in an increase in uric acid and urea nitrogen output, primarily, the latter, suggesting that alcohol may directly affect protein catabolism. There was no significant difference in fecal nitrogen excretion between experimental periods.