Don't think white rice is necessarily high fibre. I think a better option to make the point is that by this metric we should all eat celery? :)
The article mentions 'inulin' - it's a form of carbohydrate that alledgedly doesn't cause the same spike in blood sugar levels as starch. With a family history of type 2 diabetes, I have thus wondered about growing Jerusalem artichokes (sunchoke) as an alternative to potatoes.