With the improvement of people’s health awareness, more and more attention is paid to the nutrition of food. Especially in recent years, people pay more attention to the nutrition of the food when they eat. Many people tend to pay attention to the “food nutrient composition table” when buying food. It should be noted that to judge the nutritional value of food, you cannot just look at the data. Whether food is nutritious to an individual is mainly related to five aspects, namely, nutrient content, nutrient density, content of anti-nutrient factors, utilization of nutrients and nutritional contribution of food.
Nutrient content. The nutrient content of food is related to its variety, origin, cultivation, storage method, processing and cooking, and even which part of the food is eaten. The same food may have different nutrient content. Take kiwifruit as an example. Different varieties of kiwifruit have different nutrient content. The nutrient content of the same variety of kiwifruit, domestically produced and imported, is different. In addition, the nutritional content of the food is high, but the finished product after processing is not necessarily. It’s like eating walnuts can strengthen your brain, but drinking walnut beverages is bad. Eating whole grains is good for controlling blood sugar, but drinking it into a pulp, the effect is not ideal.
Nutrient density. For the “three highs” and people who want to lose weight, it is more important to pay attention to the nutrient density of food than to pay attention to the nutrient content of food. The nutrient content is the number of nutrients per 100 grams of food; and the nutrient density is calculated by calories. For every 1,000 kcal energy food, the more micronutrients the food contains, the higher the nutrient density. The high nutrient content of food does not mean that the nutrient density of the food is high. For example, when many people mention potassium supplementation, they eat bananas. In fact, bananas are very high in energy and calories. In other words, the nutrient density of bananas is not high. As a result, people with three highs or those who want to lose weight often eat bananas to supplement potassium, and calories are likely to be poorly controlled. The potassium content of tomatoes is not very high, but the calories and sugars are low, so the nutrient density of tomatoes is higher. Potassium supplementation is not just picking foods with the highest potassium content, but also choosing some low-calorie foods with good potassium content.
Anti-nutrient factors. Anti-nutrient factors are factors that hinder digestion and absorption in foods. They are found in natural foods and usually taste bitter and astringent. Anti-nutrient factors mainly hinder the absorption of trace elements in the human body, and also combine with various enzymes in the digestive tract in the body to reduce the activity of digestive enzymes. But anti-nutritional factors are not all bad. Different groups of people have different physical conditions, and they are also particular about how much and how to eat. The common ones are protease inhibitors, phytic acid, tannins, oxalic acid, goiter-causing factors, and polyphenols. Anti-nutritional factors are not terrible, and can generally be eliminated through general cooking. Common anti-nutritional vegetarian foods are as follows:
Protease inhibitors contained in beans are not conducive to absorption. As long as red beans, mung beans and kidney beans are boiled, almost all of their protease inhibitors can be eliminated. Only soybeans and black beans, because the protease inhibitors contained in them have anti-heat ingredients, they will not be completely eliminated. Therefore, you should pour out the water after soaking the beans, and then use a soymilk machine to make the pulp, the anti-nutritional factors will be as little as 12%. More cooking can reduce it to 5%. However, if raw beans are directly beaten, there will be more anti-nutritional factors remaining.
Cereals, nuts, etc. all contain phytic acid. Phytic acid will reduce the body’s absorption of trace elements such as iron and zinc. But it can be removed by fermentation and adding phytase.
Blanch spinach and leeks before eating. Oxalic acid affects the absorption of calcium, iron, zinc and other trace elements, and is also an anti-nutritional factor. Spinach and leeks are its representative vegetables. All plants have oxalic acid, but the content is different. Oxalic acid protects plants from pests and diseases.
Bioavailability of nutrients. The bioavailability of nutrients refers to the absorption of food by the human body. For some foods, what you eat is not necessarily what your body gets. Try to choose foods with fewer anti-nutritional factors and high absorption and utilization rates. To improve the bioavailability of trace elements, methods such as soaking, sprouting, and fermentation can be used to greatly reduce the activities of phytic acid, tannins, and protease inhibitors. In addition, through the combination of foods, such as eating calcium-containing foods with vitamin D, etc., the absorption and utilization of calcium can be improved.
Nutritional contribution of food. The nutritional contribution of food consists of the nutrient content of the food, the possible consumption of the food, the nutrient utilization of the food, and the availability of the food. According to the data in the food composition table, some foods have high nutrient content and high absorption rate, such as dried shrimps. But it may only be eaten a few times a year, or if you eat too much, you can’t eat it, and you only eat a few grams each time. Then it contributes less every day. The consumption of green vegetables is much larger, which naturally contributes more to calcium supplementation. In short, when comprehensively judging the nutritional value of food, the above factors must be considered.