They collected nutrition content, ingredient lists, and the presence or absence of the Whole Grain Stamp on product packages from all of these products, according to a Harvard statement.
They found that grain products with the Whole Grain Stamp, one of the most widely-used front-of-package symbols, were higher in fibre and lower in trans fats, but also contained significantly more sugar and calories compared to products without the Stamp.
The three USDA recommended criteria also had mixed performance for identifying healthier grain products. Overall, the American Heart Association's standard (a ratio of total carbohydrate to fibre) proved to be the best indicator of overall healthfulness.
