18 February 2009

Mr. Wizard on wholegrain

2old4this asks...

It's generally known that refined carbs, such as flour, are big no-no's for people on a high protien diet. Heck, it's generally known that they're just bad period!

But just how much processing results in a "refined" product? For example, oatmeal is just sliced oats as far as I can tell, so would that be OK since it's whole grain? Or is just the slicing enough processing to make it "refined?"

What about stuff like Ezekiel bread? It's even more "processed" but still called "whole grain."

Where's the line that separates just enough processing and too much processing?
If y'all have seen Mr. Wizard, you know he *knows* food. Intimately and often. So he truly appreciates these food questions. Keep 'em coming, and if you'd like, send along some cupcakes too.

When it comes to grain products, the key is the bran. The more refined the grain, the less remains of the coarse outer shell of the grain. Take a look at this cross section of a wheat kernel (click to embiggen:)

Refining takes away the outer layers of the kernel. That big white section that just *looks* like it's going to make you fat? The endosperm? If you refine your wheat all the way down to white flour, that's what you'll get. The rest will remain behind in the grist mill. The starch and protein - gluten, primarily - make great breads, cakes, and pastries - but they provide little in the way of fiber.

Leaving some of the bran coat leads to a coarser flour that leads to a larger and drier crumb in breads, but it is certainly healthier.

Your gut is right when it comes to oatmeal (if you can take the time to cook steelcut oats instead of rolled ones you'll appreciate the texture and taste quite a bit more.) Oatmeal is basically the whole grain. Oat flour can be processed from it, but it has limited use as it doesn't form as complex a crystalline structure when worked because it lacks gluten.

The biggest problem with having too many refined grains in your diet is that you get your calories too cheaply. The second big problem is that without enough soluble fiber you run the risk of GI problems.

And here comes the boilerplate advice: The Wizard recommends a balanced diet where the larger proportion of your complex carbohydrates come from whole grains; however, he also says it's a-ok to have that canoli once in awhile.