Review of new UK alcohol guidelines coming soon.

When considering large studies of alcohol consumption related life expectancy keep in mind sick quitters bias – teetotallers included former alcoholics people already too sick to drink. This may skew some research to look like not drinking is less healthy than moderate consumption.

Calories in Alcohol

If you're weight watching, then also watch your alcohol intake. Gram for gram alcohol has almost the same amount of calories as fat, and almost twice as much as found in carbohydrates.
There is a lot of variability, but roughly speaking
A pint of beer = 180 kcal
A 175ml glass of wine = 120 kcal
A 25ml gin shot (ignoring the tonic) = 180 kcal