I don’t know. Telling an alcoholic to “stop drinking” seems like pretty unambiguously directionally correct advice (albeit difficult to execute) in a way that “never eat alone” is not. In that way “never eat alone” is probably much worse advice.
"You're overweight", says the Doctor, "you need to eat less and move more." "No s*t Sherlock with my IQ of 147 I'd never managed to put that one together myself," I replied.
There are definitely better ways to discuss the topic with someone you are trying to help.