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.
"You have to be very dedicated and ensure you're getting all the nutrients you need, especially things like calcium, vitamin B12 and Omega-3, which traditionally come more from animal sources."
To help idiot-proof the process, before hitting the supermarket, I print out a list of vegan food available here from Irishvegan.ie.
Vegan dabblers, Beyonce and Jay-Z. Photo: Getty
Forest Feasts, Just Food and Celtic Chocolates are just some of the 'free-from' Irish brands I throw in the trolley, as well as some vegan-friendly Berocca and Vegamega-3 vitamin tabs, just in case.
Coffee with soya milk, a banana, a falafel (flour) wrap and a beetroot salad all tide me over until teatime on Tuesday.
Unlike last year's 5:2 Diet, where you fasted on 500 calories two days a week, at least I only have to wait until teatime before vegging out on a veggie pizza.
Since appearing on Dragon's Den with Dee's Vegan Burgers in 2010, Deirdre Collins from Cork has gone from supplying a handful of farmers' markets to hundreds of supermarkets and health stores as far afield as the United Arab Emirates.
"People often say to me: 'I could never be a vegan'," she says. "But if you've ever eaten a tin of baked beans, that's vegan food.
"There's a perception that vegan food is all weird fake meat. Real vegan food, like vegetables, nuts and seeds, is for everybody."
"Of course, not all vegan food is healthy; there are plenty of sweet treats out there as well."
By the middle of the week, I'm still hanging in there thanks to a mid-morning almond milk cappuccino and vegan doughnut at Antoinette's Bakery in Dublin 8.
Although processed foods are forbidden under the VB6 regime, I cheated when it came to lunch and grabbed a microwavable soup.
Former US president Bill Clinton is sure to have shown greater restraint when he lost 20lbs by taking a leaf out of vegan daughter Chelsea's book back in 2010.
"I've stopped eating meat, cheese, milk, even fish," the 67-year-old revealed. "I have so much more energy now. I feel great."
However, four days on, I'm still wrapping my tastebuds around the concept of lactose-free milk and wholewheat.
Not that either taste particularly bad, just different, as lapsed vegan Natalie Portman explains: "I actually went back to being vegetarian when I became pregnant."
The Black Swan actress and mother of one says: "I was listening to my body to have eggs and dairy and that sort of stuff.
"If you're not eating eggs, then you can't have cookies or cake from regular bakeries, which can become a problem when that's all you want to eat."
By Friday though, any beef I have with the VB6 diet soon disappears when I find I'm nearly two pounds down on the scales.
Lapsed vegan Natalie Portman
"For most people, if you follow a vegan diet, you will absolutely lose weight," says Aveen Bannon, who also runs the Dublin Nutrition Centre.
"Vegans tend to be slimmer as they have a lower intake of saturated [animal] fat. However, veganism is not something you should embark upon just to lose weight. It's very much a lifestyle decision.
"If you're thinking of trying it, my advice is to start with a vegetarian diet and see how you get on."
After dabbling with Bittman's VB6, I'm not there yet, but vow to flash my honorary v-card a bit more at mealtimes.
As for full-time veganism as practised by Pamela Anderson and Alicia Silverstone?
Bean there, done that.
Right now, it's back to coffee with full-cream milk, cheese and chocolate for me.
'Since I became vegan, I have more energy and I look younger too'
Stylist Roxanne Parker, 34, (www.roxanneparker.com) decided to become vegan after ending up in a hospital bed.
"Over the past two years, I've slowly changed to a fully plant-based vegan diet. It all started back in 2012 when I fell ill.
"After countless tests, I discovered that my bladder was over twice the size it should be, but the doctors couldn't tell me why.
"Desperate to get my health back, I decided to ditch dairy and meat from my diet. The result was nothing short of miraculous. Within a month, my bladder had shrank to a normal size.
"Since turning vegan, I have more energy and friends have told me that I look younger, too.
"Typically, breakfast might be porridge with almond milk topped with seeds and fruit, lunch could be a lentil salad dressed with vegan pesto and dinner, a coconut milk-based green curry with brown rice.
"Last summer I started posting photos of my vegan meals on Facebook, and the reaction has been amazing. People are always messaging me for recipes!
"You can be vegan and still be unhealthy, tucking into crisps and fizzy drinks, but what's the point? You will only look and feel terrible.
"Some people ask me if my diet is expensive, but I can honestly say I've saved a fortune by becoming a vegan.
"More importantly, knowing that I was able to cure myself through nutrition – and inspire others to make changes in their diet along the way – has been a hugely empowering experience for me."