Whole Grains: Several Groups Should Not Eat Too Much
Regular consumption of whole grains helps prevent hyperlipidemia, obesity, diabetes, colorectal cancer, and more. The benefits of eating whole grains are numerous, and it's believed that modern people are well aware of them. However, how to eat them scientifically and whether everyone is suitable for eating whole grains is a question many people don't have an answer to.
For "three-high" populations (high blood pressure, high blood sugar, high cholesterol) who are accustomed to eating refined rice and white flour and have large amounts of meat and fish at every meal, a mix of whole and refined grains helps balance nutrition and prevent chronic diseases. However, although whole grains are good, they should not be eaten in excess, especially by the elderly and those with poor gastrointestinal function.
Take sweet potatoes, for example. Although they are an inexpensive and delicious health food, due to their special sweet potato starch and fiber, if not steamed or cooked thoroughly, they can easily produce acid and gas in the digestive tract, causing discomforts like bloating and heartburn. Therefore, eating sweet potatoes also requires some consideration. First, eat them cooked, not raw. The large amount of starch in sweet potatoes is wrapped in a tough cell membrane, which the body can only easily digest and absorb after being thoroughly cooked or steamed. At the same time, cooking can destroy most of the oxidase, reduce gas production, and avoid bloating. Second, do not eat too much at one time, and control the daily total. The downside of sweet potatoes is their low protein and fat content. Eating too much can affect the intake of other foods and may also interfere with the absorption of other nutrients. The correct way to eat them is to keep rice, flour, etc. as the main staple in your diet, and to pair it with 100-200 grams of sweet potatoes. Associate Professor Chen Chaogang explains that there is no fixed time for eating sweet potatoes; they can be eaten with a meal or as a snack. Eating them for breakfast or lunch can better help delay hunger in the morning or afternoon.
Sweet potatoes are low in protein and fat, so it's best to eat them with high-quality protein foods like milk and meat. On the market, there are red-fleshed sweet potatoes, purple-fleshed sweet potatoes, and pale yellow-fleshed sweet potatoes. Different varieties have some differences in their content of carotenoids and plant active substances. The redder or yellower the color, or the deeper the color, the higher the content of antioxidant nutrients.
The elderly have poor gastrointestinal function, and infants and young children have immature gastrointestinal systems, so they should not eat large amounts of sweet potatoes or other coarse grains at one time. If too many coarse grains are eaten, it will affect digestion. A large intake of fiber at once can lead to acute symptoms like intestinal obstruction and dehydration. Long-term excessive consumption of coarse grains can also affect the absorption of certain nutrients. The so-called "pale complexion from a poor diet" is a typical manifestation of malnutrition caused by eating too much fiber. Fiber can also interfere with drug absorption. It can reduce the effectiveness of certain cholesterol-lowering drugs and antipsychotic drugs. For people with weak gastrointestinal function, eating too much food fiber is a great burden on the stomach and intestines.
Who should be cautious about or eat fewer coarse grains?
People deficient in elements like calcium and iron. Coarse grains contain high levels of phytic acid and dietary fiber, which can bind with elements like calcium and iron, reducing their absorption.
People with digestive system diseases. If suffering from liver cirrhosis with esophageal varices or a stomach ulcer, consuming large amounts of coarse grains can easily cause rupture and bleeding of the varices or ulcer bleeding.
People with low immunity. If the daily fiber intake exceeds 50 grams for a long time, it can hinder protein replenishment, reduce fat utilization, and cause damage to the functions of organs like bones, the heart, and blood, thereby lowering the body's immune system.
People engaged in heavy physical labor. The energy in coarse grains is relatively lower than that of common grains, and they are low in protein and fat, making it difficult to provide comprehensive nutrients for people engaged in heavy physical labor.
Adolescents in their growth and development period. Due to the special nutritional and energy requirements for growth and development and the physiological needs for hormone levels, coarse grains not only hinder the absorption of cholesterol and its conversion into hormones but also interfere with the absorption and utilization of nutrients.
The elderly and children. The elderly have reduced digestive function, while children's digestive function is not yet fully developed. Digesting a large amount of food fiber is a great burden on the gastrointestinal system. Moreover, the absorption and utilization of nutrients are relatively low, which is not conducive to children's growth and development.
What are coarse grains?
Coarse grains generally refer to millet, brown rice, oats, corn, sorghum, barley, black rice, etc. Coarse miscellaneous grains refer to soybeans, mung beans, potatoes, Chinese yams, sweet potatoes, etc. Nutritionists point out that because modern food is too refined, it is very necessary to consume coarse grains appropriately every day. However, one should not only eat coarse grains; it is important to mix them with refined grains. When eating coarse grains, it is also necessary to pair them with nutrient-rich foods, such as fish, dairy, and eggs. Some people with poor digestive function can process coarse grains finely, for example, by cooking them into a porridge before eating.