I don't have a great answer, but I identify with the question. I also haven't really landed on the thing I feel comfortable/ok saying, and I also feel honesty would hurt me professionally.
My close friends and family members I told. My parents I told "alcohol just isn't agreeing with me these days." [My mother, an alcoholic in big time denial herself, is having trouble with this and keeps asking. "Maybe you have a gluten allergy," she says. Oh boy.]
With others, including work situations, if it's people who have never seen me drink I just say "alcohol doesn't agree with me." If it's people who have seen me drink before, I say "I was having some health issues, and I found I felt better if I didn't drink." If they press further I say troubles with my stomach or troubles sleeping. People don't go much further with that usually.