Energy value of moderate alcohol consumption by humans.

We investigated the effects of an equal-energetic substitution of ethanol for dietary carbohydrate in high-and low-fat diets on energy expenditure and body composition. During the controlled feeding study, subjects maintained their weights and consumed only food and drink provided by the US Department of Agriculture Beltsville Human Nutrition Research Center's Diet Study Facility. Subjects (16 men and 32 women) were divided equally into two groups and consumed either a high-or low-fat diet for 16 wk. The feeding period was divided into two 8-wk periods during which either ethanol or carbohydrate was added to the diet (5% of total daily energy intake) in a crossover design. The metabolizable energy content of the diets (with supplements) was determined for all subjects through measurement of total food intake and fecal and urinary losses for 7 d during both 8-wk periods. Energy expenditure, measured for 24 h in a room calorimeter at the end of each 8-wk period, was the same for both periods. Metabolizable energy intake and changes in total-body energy content were used to calculate the total amount of energy expended by each subject for 7 wk during each 8-wk period. Total energy expenditure for 7 wk was the same when subjects consumed either ethanol or carbohydrate. These data clearly show that on an energy basis ethanol and carbohydrate are utilized in the diet with the same efficiency. These data are consistent with the efficiency of use of alcohol for maintenance of metabolizable energy being the same as that for carbohydrate.