I spoke to my friends at the Jacob Leinenkugel brewery in Wisconsin and they tell me that this is not true. There are many 'bitter' beers, just the same as there are many 'lager' beers. The calories in the drink vary according to the brew. They referred me to this site that gives many specific examples and lots of good information http://hbd.org/brewery/library/AlClbinger.html
roughly the same - if you want to lose weight stay off both as the sugars in them turns directly to fat and is not used as immediate energy unlike other carbs - drink shorts with slimline mixers if you need an alcoholic fix!