I've been big and strong on nearly every diet known to man. Even Doug Graham's 80/10/10 raw vegan diet. The key is, calories, calories, calories. But doing it healthfully is important too. You don't want too many oils, especially olive oil. Olive oil slows digestion and makes food travel through your digestive system more slowly. Not good when you're eating a lot of fruit or grains. This is instant fermentation and you'll quickly be a host for molds, parasites, and candida. One of the best ways to bulk up as a vegan I've found, is trail mix. Get an organic trail mix, or make your own. Get the mycotoxin free raw peanuts from rawfood.com, get raw cashews, goji berries, raisins, and so on. You can down 1,000 without blinking an eye, and they're healthful calories. Calories are king.