20 units is not moderate, it borders on the safe limit for men of 21 units and exceeds the limit for women by quite a large margin. Alcohol recommended safe limits, units/week.
funny man - the Royal College of Physicians admit they just made these numbers up on the basis of no evidence at all. In NZ the limits are more than twice as high and they are not exactly dropping dead in the streets. The WHO says below 35 units is low risk . Even supposing anybody tells the truth about how much they are drinking to any studies that are done.