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Much of what is known about whole grain content of food is based on what is reported on food packaging or in recipe books. Few countries have clear guidelines for labeling whole grain content, which limits the value of a product labeled as “whole grain” for estimating intake or for consumer communication. There are three main approaches to quantifying whole grain content in food:

 The percentage of the grain ingredients that are whole grain (i.e., whole grain vs. refined grain)

 The percentage of the product dry weight that is whole grain (i.e., without the influence of water added during food processing or cooking)

 The percentage of the product as consumed that is whole grain (i.e., accounting for non‐grain‐based ingredients)

The United States Dietary Guidelines for Americans, in their practical advice for helping consumers select whole grain products, advise that selecting products with “whole grains as the first ingredient” is a good consumer shortcut for choosing foods that will provide a substantial proportion of whole grains. However, it still falls short as a quantitative tool, and from a regulatory and consumer perspective, requires knowledge about ingredient lists and close‐up investigation of the back of the packaging to make this crude measurement of whole grain content.

Most cereal foods have water added, and depending on what is quantified, this may make a big difference to a whole grain label that is based on percentage of a product’s weight as consumed. For example, dried pasta contains essentially no water, and if made from only whole grain durum wheat, could be labeled as “100% whole grain pasta.” The same pasta cooked and frozen for a ready meal would be only 33% whole grain if reported on a fresh weight basis, although the amount of dry pasta in a serving would be the same. This highlights the need to account for water content when reporting whole grain content in foods.

A further issue is that of the effect of processing – at what point do whole grains become so highly processed that they are no longer whole grain? There are few guidelines and this topic is somewhat out of scope here, though it is worth mentioning that the United States Department of Agriculture (USDA), in 2008, stated that when a shoot from a sprouted cereal seed is longer than the seed itself, then it is no longer considered a grain, but has become a vegetable. Others have also suggested that once more than 10% of the dietary fibre has been removed or disintegrated then the resulting ingredient or product can no longer be considered to be whole grain.⁽¹⁾ However, this is complicated, as total dietary fibre may not reflect the effect of processing that can have a major impact on biological function⁽⁷⁾ even if total fibre does not change. For example, some water soluble compounds may be leached out during boiling of cereal products.

Currently, two “user friendly” and accurate ways to report whole grain content are available in different parts of the world, helping researchers, consumers and policy‐makers alike. The first is the QUID labeling used in Europe (see earlier), which clearly documents any whole grains as a percentage of the product as consumed.⁽¹⁾ The second is the Whole Grain Stamp, a labeling certification programme offered through the non‐profit Oldways Whole Grains Council, which displays the grams of whole grain ingredients per serving of more than 13,000 products in 63 countries.

An important additional aspect of quantifying whole grain content is to report the proportion of different grains. As interest in understanding the differential effects of different grains increases, breaking down daily whole grain intake into different types of grain is necessary^(8,9): whole grain oats or rye, for instance, may be associated with different health benefits than whole grain wheat or barley. This is usually done with QUID labeling, and is recommended as part of guidelines for whole grain food labeling.⁽¹⁾