Like eating more vegetables and fruits, eating more whole grains is also one of the elements of a healthy diet. The low-nutrition and high-glycemic properties of fine grains (fine grains) such as white rice, white buns, white bread, white noodles, and instant noodles make it a key feature of poor diet structure.

　　 coarse grains include coarse grains in the traditional sense, such as millet, corn, sorghum rice, buckwheat, oats, various miscellaneous beans, etc., as well as whole wheat (such as whole wheat bread, whole wheat buns, Whole wheat flour) and brown rice etc. Their common feature is that without fine processing, the outer skin and outer layer of grain seeds or legume seeds are retained as much as possible.

The nutritional quality of coarse grains is better than that of fine grains. First, coarse grains contain more vitamins and minerals. Second, coarse grains are an important source of dietary fiber. Third, coarse grains have a low "glycemic index" (GI), which helps prevent and treat insulin resistance. Fourth, coarse grains are rich in phytochemicals, such as polyphenols and terpenes, which help prevent various common chronic diseases. In comparison, finely processed cereals (fine grains) have low levels of vitamins, minerals, and dietary fiber, fast blood sugar (high blood sugar production index), and almost no phytochemicals, which is not conducive to the prevention of various chronic diseases.

　　 "Thickness and Thickness" is a well-known principle of healthy eating. All along, there is another subtext of thickness and thickness collocation: "Thickness and collocation is mainly based on fineness". But now it seems that a healthy diet should be "a combination of thickness and thickness, with emphasis on thickness". That is, the amount of coarse grains should be increased. The “Dietary Guidelines for American Residents 2010” recommends that whole grains (coarse grains) account for at least half of cereals. "Dietary Guidelines for Chinese Residents 2007" recommends eating 50 to 100 grams of coarse grains every day, which accounts for about 1/4 of the cereal intake. The latter proposal takes into account the fact that the total cereal intake of Chinese residents is much larger than that of American residents.

　　 At present, the intake of coarse grains of the vast majority of urban residents is far from the recommended amount. Occasionally drinking a little millet porridge, eating tortillas is not enough. To achieve sufficient intake of coarse grains, daily staple foods such as rice, buns, bread, and noodles must be completely transformed. Replace white rice with multigrain rice (mix more millet, black rice, brown rice, barley, red beans, mung beans, kidney beans, corn ballast, etc. as appropriate when making rice); replace white buns with whole wheat buns (use whole wheat flour or some whole wheat) Wheat flour); replace white bread with whole wheat bread; almost all pasta such as noodles, bean bags, rolls, etc. must be mixed with some whole wheat flour. In short, the existing staple food must be comprehensively upgraded, "more coarse and less fine", "more black and less white".

　　Many people preconceived that coarse grains were not tasty. In fact, as long as the cooking method is proper, the taste of coarse grains is not only inferior to that of fine grains, but also has a more natural mellow taste than fine grains. Others mistakenly believe that coarse grains are difficult to digest and damage gastrointestinal function. In fact, fine grains were popularized only after the invention of the roller mill in the 19th century. In the long history before that, humans mainly lived on coarse grains.