I don't known about "loose" abdominal fat, but to lose abdominal fat, diet is very important (there is a saying that "six packs are made in the kitchen") especially for those of us who tend to store our fat there. Sometimes, it's impossible to completely get rid of the ab fat without getting too skinny elsewhere (I have that problem).
Any program that helps reduce body fat will help with this (diet, cardio to burn calories, resistance training emphasizing working the large muscle groups of the legs, back and chest, or that uses multiple muscles at the same time to burn more calories).
Core work is good to keep those muscles in shape.
As for alcohol and dieting: a gram of alcohol has 7 calories (vs. 9 for a gram of fat, and 4 for either a gram of protein or carbohydrate). Also, I've read that alcohol consumption keeps your body from burning fat. And because it can increase your appetite, it can contribute to weight gain (especially if what you eat when drinking is high fat, so it will tend to be stored rather than used for fuel).