"The More Your Jaw Has To Work, The Better"

Here is a scientific explanation behind Casa de Luz's ongoing elimination processed grains from Casa de Luz.  Dr. Andrew Geil explains why whole grains have a low glycemic index whereas processed carbohydrates--including those made with flour or puffed grains--have a high GI (the "Glycemic Index" is a ranking of carbohydrate foods on the basis of how they affect glucose, i.e., blood sugar). 

The reason is that it takes longer for digestive enzymes to reach the starch inside whole grains or grains cracked into large pieces, slowing down the conversion of starch to sugar.   But when grains are pulverized into flour, whether whole or not, their surface area expands dramatically, providing a huge, starchy surface area on which the enzymes can work. Consequently, the conversion to sugar happens very quickly. 

You can be pretty sure you're eating a natural grain with a low GI ranking if you have to chew it or can see grains or pieces of grains in food products. The more your jaw has to work, the better.   This is while grains that are freshly milled (i.e., processed) into flours are fresher than purchased flours they are nonetheless processed and convert more quickly to glucose.