Effects of Alcohol Metabolism
Body Weight. Although alcohol has a relatively high caloric value, 7.1 Calories per gram (as a point of reference, 1 gram of carbohydrate contains 4.5 Calories, and 1 gram of fat contains 9 Calories), alcohol consumption does not necessarily result in increased body weight. An analysis of data collected from the first National Health and Nutrition Examination Survey (NHANES I) found that although drinkers had significantly higher intakes of total calories than nondrinkers, drinkers were not more obese than nondrinkers. In fact, women drinkers had significantly lower body weight than nondrinkers. As alcohol intake among men increased, their body weight decreased (17). An analysis of data from the second National Health and Nutrition Examination Survey (NHANES II) and other large national studies found similar results for women (18), although the relationship between drinking and body weight for men is inconsistent. Although moderate doses of alcohol added to the diets of lean men and women do not seem to lead to weight gain, some studies have reported weight gain when alcohol is added to the diets of overweight persons (19,20).
When chronic heavy drinkers substitute alcohol for carbohydrates in their diets, they lose weight and weigh less than their nondrinking counterparts (21,22). Furthermore, when chronic heavy drinkers add alcohol to an otherwise normal diet, they do not gain weight (21). Source:Alcohol Metabolism