You Ask, I Answer: Fiber

Why [do] some food labels (fiber one, gnu food bars, etc.) eliminate the calories that cannot be digested because they are from fiber in the overall calorie count whereas other food labels may not? Isn't there some FDA standard??

-- Anonymous (via the blog)

Actually, the Food & Drug Administration allows food manufacturers to not take grams of insoluble fiber into account when tallying up their caloric totals.

Remember – wheat bran is the only food that is 100% insoluble fiber.

Thus, it is not surprising that cereals consisting solely of wheat bran -- like Fiber One -- do not count calories from this specific fiber.

When it comes to foods containing a mixture of soluble and insoluble fibers – such as the lentils in a soup – fiber grams are not subtracted from total carbohydrates.

Why doesn't soluble fiber get the same free pass?

Unlike its insoluble cousin which passes right on through our digestive system, soluble fiber is metabolized by bacteria in our colon.

This results in the production of short-chain fatty acids, which are involved in many processes, including glycolysis (the breakdown of glucose).