The higher the proof the more calories. For example 1 1/2 ounces 80 proof contains 97 calories and it just goes up from there.
7.5-ounce gin and tonic: 171 calories and a 3 ounce whiskey sour: 122 calories..thats not too bad at all unless you need a lot to get a buzz goen.
If you go to the pub you can still drink beer just maybe watch what you are eating with it. Most people eat high calorie snacks when drinking so maybe cut back on those.
http://www.theraven.com/beer.html
That site has a list of beers and their calorie content.