I've been watching what I eat but, from time to time, I go out for a few drinks. Assuming I use either no mixer or a non-caloric mixer (e.g., diet cola), does it make a difference what liquor I drink (vodka, scotch, rum, scotch, etc.)? A bartender I know says that drinking vodka is better than scotch or rum because of their sugar content. But I know that none of those liquors have any carbohydrates, so I'm confused. Can anyone help?