BOSTON — A whole grain ingredient must have 100% of the bran, germ and endosperm of the original kernel — all the essential parts and naturally occurring nutrients of the entire grain seed in their original proportions. That description, provided by the Whole Grains Council, seems simple.

But leave it to the regulators to complicate things. In Canada — but not the U.S. — wheat flour can be called “whole wheat” even when up to 5% of the original kernel is missing. That forces two different wordings in ingredient listings on packages. In Canada, “whole wheat flour” designates the version containing contains at least 95% of the original kernel, but “whole grain whole wheat flour” is the 100% content.