Warning: I'm no nutritional expert
I lost 55lbs and gained a lot of muscle doing in intense 2 day a week weight training over 10 months. If you are trying to lose fat and gain muscle, simple sugars and carbs are not good! Milk, and all dairy, is chalk full of sugars and should be avoided if your goal is fat loss. This includes fat free milk (read the sugar content). Most carbs are just complicated sugars; it all turns to fat when your body processes it. I don’t know how to do this on a vegan diet. I mostly ate whey protein, egg whites, chicken and fish and LOW carb (high fiber) veggies like broccoli. If you go full veggie, getting ample protein to gain muscle is going to be your challenge. Carb loading is only good before you expend energy, so eat high carb in the morning if you have to. Eat good carbs that aren’t processed or full of sugar. Corn is sweet and taste good because it is packed with sugar and starch, that’s why that feed it to live stock. Potatoes (baked) and oats are good carbs.
When in doubt, on a weight loss mission, make sure your:
Veggies are low glycemic index
Your protein is fat free
Eat low GI carbs in the morning