CONSUMING ALCOHOL CONTRIBUTES TO WEIGHT GAIN. Answer: True. Alcoholic beverages usually contain a lot of calories and consuming them in large quantities can contribute to weight gain. For example, 12 ounces of regular beer can contain about 140 calories on average. A 150-ml glass of white wine contains about 120 calories. Some cocktails, such as a daiquiri or pina colada with white rum can contain up to 450 calories for a 250-ml glass. Admittedly, this warrants some thought… as well as moderation!