As a vegetarian, you'd think that going the whole hog by giving up animal products altogether would be a cinch.
After all, even steak-lovers Beyonce and Jay-Z survived a much-Instagrammed '#22dayveganchallenge' before Christmas.
So how hard can swapping anything with a pulse for pulses before 6pm be?
That's the premise of this year's hottest new diet book, VB6 by Mark Bittman.
By going vegan for breakfast and lunch, and eating whatever you want after the Angelus, it promises you will "lose weight and restore your health for good".
The best-selling Bittman shed 35 pounds himself on the plan, and even reversed his pre-diabetes condition.
And if it's good enough for Bey, it's good enough for me, so armed with a copy of the book, I'm becoming a born again vegan for one working week. Black Bean Tacos with Tangy Cabbage and Eggplant (aubergine) Un-Parmesan are among the more adventurous vegan recipes that appear in the book.
I get off to a good start on Monday with super-healthy porridge made with soy milk followed by an orange.
My lunch menu appears grim when I realise that breakfast was about the only vegan-friendly thing in the whole house.
Deirdre Reynolds. ‘By Friday, any beef I have with the VB6 diet soon disappears when I find I’m nearly two pounds down on the scale. Photo: Ronan Lang
Even the meat substitute I've been using since going veggie four years ago, which I assumed to be vegan, lists egg among its ingredients.
A sad-looking salad cobbled together from the contents of the fridge – lettuce, peppers and tomatoes – and a snack of carrot sticks will just have to sustain me until six o'clock instead.
"Going against the grain by joining the 6pc of Irish people who don't eat meat isn't easy," says Aveen Bannon, dietician with fruit and veg supplier Keelings. "Ireland is not a very vegan-friendly country. Historically we're a very meat-eating culture.
"Even today, if you go out to a restaurant, there might be one vegetarian or vegan option on the menu.
"People are definitely starting to experiment with things like nuts, seeds and beans more," she adds. "They just don't really know what to do with them.
"The vegan diet is a very healthy diet, but it's also very difficult.
Vegan dabblers, Beyonce and Jay-Z. Photo: Getty