Hi Narnea
I have no problems at all, in fact if anything, I think a vegan diet works very well with this approach as veggies & tofu are low calorie and pulses, though a bit higher, are very filling. I’ve been vegan for over a year, and with the exception of one year, was lacto-ovo vegetarian for 20+yrs so I am used to not using meat and to a lesser extent dairy. Curries, stews, soups, stir fries, etc are all good. I’m currently doing 3 days at 800cals and mostly low carb med. For breakfast I typically have 20g oats, 20g crunchy natural peanut butter, 100g soya yoghurt, 50g strawberries. Lunch is usually a homemade soup, salad with pulses/hummus, or tofu scramble. Dinner is often a Socca pizza (from the book I mentioned) & salad, pulses curry or stir fry with tofu/tempeh. And I still have calories for my cocoa with a little oat milk in the evening. It is worth noting though that because I have chronic fatigue and can’t work, my activity levels are low. For someone who is much more active it might be harder.
You could always try swapping one meal per fast day or having one fast day each week as vegan and see if you can adapt over time.
Hope that helps.