Well i suffer from an eating disorder, so it's hard to tell for me.
But what i often did was replaced alcohol with food.
However, i read that alcohol has a chemical effect on the body that stops the body from burning off calories.
Combine this with alcohol that may have a high calorie and carbohydrate count and your on the road to weight gain.
I don't know about you guys but the next morning after drinking I'd be feeling so bad that I'd end up eating junk so it easily ruined any efforts of weight loss for me. @.@