Alcohol is a carb, but it is handled by the body somewhat differently than other carbs. The calories in Alcohol are burned first as energy, which delays ketosis until they all are consumed. The only good thing is that Alcohol calories are not converted to fat like breads, pastas, and rice. Alcohol serves to delay weight loss because the body is forced to burn these calories first. The other bad side effect is that it tends to lower inhibitions and therefore people sometimes eat things that are not on their diet.

Alcohol is also a diuretic and abuse of any diuretic can lead to kidney damage, cardiac arrhythmias, electroltye imbalance, heart palpitations, dehydration, fluid retention, headaches, potassium deficiency, and dizziness.

So a beer or glass of wine every now and then won't kill you, but it's going to slow down your weight loss, possibly cause you to make bad food choices. This is mostly why Atkins is against using alcohol.

Regards,
Lux