none of that B.S. NIH crap where 3 drinks / day makes you a raging alcoholic. these are, and always have been, the tiers of drinking:
no drinks - abstinence
less than 5 drinks / week - light drinking
5-15 drinks per week - moderate drinking
15-30: heavy drinking, bordering alcoholism
30-50: very heavy drinking, alcoholic
50-70: extremely heavy drinking, severe alcoholic
70+ - destructive alcoholism
these number apply to a health adult male, around 180 pounds. 1 drink = one 4 oz glass of wine, 12 oz can of beer or a 1.5 oz shot of 40% alcohol.
genetics determine to a certain extent where one falls into these levels, but generally they are correct.
anything else is false.