#3 is good and I do this #longevitarian and #quotidian fasting. I only eat one meal a day and it's dinner or lunch, but I do vegan keto. You can also substitute beans, lentils and dark greens for example, yeast for B-12 etc. Also, carbs are not so much an enemy when you know how to use them for endurance power the next day as they sustain longer. Potatoes are amazing for vegan athletes. Everything changes when you're vegan. You can eat all the carbs you want, everything is made of them. White flour is the devil though, true that.