Oat flour vs Rice flour vs Tapioca Starch


So I came across an Asian market local to me that has cheap rice flour (both “sweet” and normal variety) as well as tapioca starch. My initial DIY recipe had a base of oat flour but since in order to get that cheaply I need to order in 50 pound amounts online I was wondering if it’d be smarter to use rice or tapioca as a base.

Is there a bad reason not to use these instead of oat flour? My main concern is with glycemic index. Has anyone used these instead if an oat base?


Check the macro and micro compositions, of course, but if all you care about is starch, then both rice and tapioca are starches that people eat all over the world.

A good place to find info on glycemic index should be here: http://www.glycemicindex.com/