Hi folks.

I've recently gone vegan and I'm trying to figure out how I should get my
calories. Can someone check my thinking here...

My target weight is about 10 stone, and according to an online BMI
calculator this means I need about 2000 calories per day to maintain that
weight.

The book called The Optimum Nutrition Bilbe says I should get 70% of these
calories from carbohydrates (and 15% from fat and 15% from protein). If
carbohydrates give me 4 calories per gram, that means I need about 350 grams
of carbohydrates per day. Looking at my carbohydrate counter book, it looks
as though vegetables contain maybe one sixth carbohydrate by mass (using
potatoes as an example). So that means that I need to eat about 2.1 kg of
vegetables (or potatoes at least) every day. In fact, it looks to me like
most vegetables are much less than one sixth carbohydrate by mass so I would
need a lot more than 2.1kg if I had a varied diet.

That seems like a heck of a lot of veg to me. I doubt I could eat that much.
So I think my maths must have gone wrong somewhere. Can anyone tell me where
I've gone wrong?