As reported on several occasions, both animal rights activists and environmentalists would very much appreciate it if everybody agreed to quit eating meat and dairy.
However, it is highly unlikely that human society will ever manage to give up on the practice of feasting on meat and cheese, so perhaps these animal rights activists and environmentalists might wish to start promoting flexitarianism instead.
For those unaware, a flexitarian is a person whose diet mainly consists of fruits and vegetables, but who does not shy away from a roast chicken or a steak every once in a while. In other words, they are both vegetarian- and carnivore-wannabes at the same time.
Granted, some would say that being a flexitarian is no more and no less than being a cheating vegetarian, yet this does not change the fact that partly giving up on meat trumps not giving up on it at all, at least as far as personal wellbeing and the environment are concerned.