Give up butter? For a whole month? In the darkest, dankest, most bleak time of the year?
You must be joking.
Yet the organisers of 'Veganuary' estimate that 350,000 people will be embracing a plant-based diet this month.
That means no meat, no fish, no animal products. It has become wildly fashionable to be a vegan - even temporarily - and while I've no doubt that some people are doing it for the sake of the planet, plenty more are doing it for the sake of their social media profile.
Look what a kind, caring, compassionate individual I am, denying myself all this wicked food!
The combination of joyless puritanism and pious virtue-signalling provided by faddish stunts like Veganuary is ideally suited to the self-regarding yet self-flagellating times we live in.
Look, I have no problem with genuine vegans who have chosen to adopt this lifestyle for their own reasons, be they health or environmental ones, and are just minding their own business.
My beef is with the zealots, the militants, the evangelical nutters who storm butcher's shops and restaurants, attempting to browbeat, emotionally blackmail or physically prevent other people from eating meat. For these people, and their online adherents, veganism is not a fashion, it's a religion, and an intolerant, fundamentalist one at that.
In fact, a tribunal has now officially deemed that ethical veganism is a "philosophical belief", akin to religion, and should be protected by law.
The landmark case was brought by vegan Jordi Casamitjana, who claimed he was sacked by the League Against Cruel Sports because of his ethical veganism, though his former employer said he was dismissed for gross misconduct and that it was "factually wrong" to connect Mr Casamitjana's dismissal to his veganism.
The key point is that the judge in the case ruled that ethical vegans should be entitled to similar legal protections in British workplaces as those who hold religious beliefs.
I have no wish to see vegans discriminated against, but neither do I want to see vegan zealots indulged.
What will the consequences of this ruling be? For instance, could a vegan employee claim to have her or his rights infringed if their colleague eats an outrageously evil ham sandwich at a communal desk? Or even a cheese sandwich, come to that, made from milk stolen from a poor cow's udders?
Mr Casamitjana himself takes his beliefs so far that he walks instead of taking the bus - come on, you don't think he'd do something so vile as owning a car, do you? - because he's worried about the vehicle squishing insects.
But Jordi, have you thought this through? Because you yourself might unwittingly step on a passing snail as you trot along the pavement, which would be a horrible stain on your conscience. Safer by far never to leave your home, though even there you have the risk of hoovering up a spider.
Even if you stay in bed all day, you might crush and accidentally murder a stray bed bug. Could you live with yourself after that, Jordi?
I'm being facetious, of course, but the craze for veganism - taken to its logical extremes - is both loopy and seriously scary.
And often it's not half so healthy, nor so environmentally friendly, as the fanatics like to think.
Many meat and dairy alternatives are highly processed foods, or are packed with sugar or salt. And the scale of food miles on fruit and vegetables beloved of vegan-dieters is astronomical. How do they think all those pomegranates, mangoes and goji berries get here - on the back of a passing butterfly's wing?
Then there's the knock-on consequences. Prices of favourite vegan products like quinoa - a kind of blah-tasting grain - and the ubiquitous avocado have been inflated so much by Western demand that people who rely on them as staples in their countries of origin can't afford to buy them any more.
Here's the thing - you don't have to go all-out vegan to improve your own health and the health of the environment. I like the simple advice of US author Michael Pollan: "eat food, not too much, mostly plants".
If it concerns you, you might also consider cutting out intensively farmed meat, where animals are reared in awful conditions, and eating as much local produce as possible.
Militant vegans would like to meat-shame - or dairy-shame - us all with their aggressive moral grandstanding. But it's none of their business what the rest of us choose to eat.
Now I'm off for a delicious piece of toast, dripping with lavish amounts of lovely Northern Irish butter.
Forget Veganuary - who's with me?