The content of oxalic acid in coarse grains is generally high, and oxalic acid will always be absorbed by calcium and iron, so it will have certain adverse effects on people with calcium deficiency and anemia. Long-term food intake in protein is low, meat food is basically not consumed, and malnutrition will occur.
Extended data:
People with chemical problems (such as gastric ulcer and duodenal ulcer) are not suitable for eating whole grains, because these ingredients are rough and physically rub the gastrointestinal tract, which will cause wound pain. People who are prone to flatulence are uncomfortable when they eat too much. Processing whole grains into coarse grain beverage, changing from eating whole grains to drinking whole grains, gives people a refreshing feeling, which not only retains the nutrients beneficial to human health, but also has a better taste, which is more convenient to drink and easier to absorb.
References:
Baidu encyclopedia-miscellaneous grains