Intakes of whole grains and other foods were assessed using validated food frequency questionnaires (FFQs) every 2 to 4 years.22 (link),23 (link) The FFQs inquired about average consumption of foods (with a pre-specified portion size) during the previous year using nine categories of intake frequency ranging from “<1/month” to “6+/day”. Open-ended questions were included for breakfast cereal brand names and foods that were not listed on the FFQ.
Intakes of whole grain (g/d) were estimated from all grain-containing foods (rice, bread, pasta, and breakfast cereals) according to the dry weight of the whole grain ingredients in each food.24 (link)–26 Whole grain consumption from breakfast cereal was derived from more than 250 brand name cereals based on information provided by product labels and breakfast cereal manufacturers. In our study, whole grains included both intact and pulverized forms containing the expected proportion of bran, germ, and endosperm for the specific grain types. By definition, the following foods/ingredients were considered as whole grains: whole wheat and whole wheat flour, whole oats and whole oat flour, whole cornmeal and whole corn flour, whole rye and whole rye flour, whole barley, bulgur, buckwheat, brown rice and brown rice flour, popcorn, amaranth, and psyllium. In the FFQ, we further asked the frequency of consuming added bran (oat bran and other bran) and added wheat germ. Intakes of bran and germ were derived directly from whole grain foods and those added to foods. Total bran and total germ are the sum of intakes from both sources.
Intakes of whole grain (g/d) were estimated from all grain-containing foods (rice, bread, pasta, and breakfast cereals) according to the dry weight of the whole grain ingredients in each food.24 (link)–26 Whole grain consumption from breakfast cereal was derived from more than 250 brand name cereals based on information provided by product labels and breakfast cereal manufacturers. In our study, whole grains included both intact and pulverized forms containing the expected proportion of bran, germ, and endosperm for the specific grain types. By definition, the following foods/ingredients were considered as whole grains: whole wheat and whole wheat flour, whole oats and whole oat flour, whole cornmeal and whole corn flour, whole rye and whole rye flour, whole barley, bulgur, buckwheat, brown rice and brown rice flour, popcorn, amaranth, and psyllium. In the FFQ, we further asked the frequency of consuming added bran (oat bran and other bran) and added wheat germ. Intakes of bran and germ were derived directly from whole grain foods and those added to foods. Total bran and total germ are the sum of intakes from both sources.
