It’s not worth trying to persuade anyone to become vegan, for a couple of very good reasons: one, it’s a losing battle, and two, it’s far from certain that a diet with no animal products is best for everyone. It’s increasingly evident, however, that a part-time vegan diet — one that emphasizes minimally processed plant food at the expense of everything else — is the direction that will do the most to benefit human health, increase animal welfare and reduce environmental impact. The remaining challenge, an undeniably big one, is to figure out how to make such a diet, which you might also call “flexitarian,” the standard.

My own diet, which I call Vegan Before 6 (and wrote a book about), is one way of tackling part-time veganism, but it isn’t the only way. An intelligent adaptation of the Mediterranean diet, one of the popular “fast today, feast tomorrow” diets or even a so-called paleo diet — one that stresses vegetables rather than animal products (our great ancestors, after all, were gatherer-hunters who saw meat not as routine but as an occasion to feast) — can put you on the right track.

As can this: a day of your choosing when you just go vegan.

There are, of course, true vegans who will say that part-time veganism is a little-bit-pregnant kind of thing; that is, impossible. But since the word means a diet without animal products, it can be used to describe something as part-time as a meal: a salad is, after all, a vegan meal. (I am aware, having had this argument dozens of times in the last few years, that many full-time vegans’ primary concern is animal welfare, and that’s a different discussion.)