I think the original post is asking about a specific chapter in the SB book where the Dr. explains that beer is the worst of the alcohols because the maltose form of carbohydrate is the most quickly metabolized. While this might be true, it does not change the fact that a light beer is fairly low carb.

So, can you have a light beer? Sure! Does it have calories? Yes! If you have a beer with a meal, your body will burn the alcohol first and store the fat for later. Your options are to enjoy your beer and have a minor setback on your diet, or don't drink the beer and be the only sober bloke in the bunch.