Er, so what are veg then, if not carbs…? Clue's in the word carbo-hydrate, basic chemical structure, Carbon, Hydrogen and Oxygen. Vegetables are primarily comprised of cellulose, as it's what forms the cell walls and gives them structure. Carbohydrates are anything that isn't a lipid (fat) or a protein, it isn't a euphemism for bread and potatoes.
Cellulose is a complex carbohydrate, as it is comprised of thousands of glucose molecules (glucose is the basic carbohydrate 'building block', all carbohydrates are comprised of glucose, which is what has the effect on your blood sugar). Whilst some carbs are necessary, the NHS's "two-thirds starchy carbs" eat well plate is basically a fast-track to obesity (why do you think pasta is so beloved of bodybuilders looking to bulk up…?). Grains are also wholly indigestible as we lack the enzyme (phytase) necessary to break them down (we also lack oxalase which is necessary to break down oxalic acid (as is found in leafy greens).
A vegan diet is, by definition, a 100% carbohydrate diet (forget the fact that plants contain protein, it's biochemically useless to us).
