Whenever we talk about dietary fiber in food, we tend to think of the ribs in celery, Chinese cabbage, and Chinese chives. In a health maintenance program, the emcee asked the audience which vegetable contains the highest content of dietary fiber. At last, most of the audience selected celery, and the rest selected Chinese chives. When they were asked why they selected that, they answered they learnt it from TV or experts.
Do you really know “dietary fiber”?
According to the survey of SAMLY ETIT Nutrition and Health Research Center, it is a common misunderstanding to believe vegetables with ribs are the main source of dietary fiber. To understand why, consider the definition of dietary fiber.
The so_called dietary fiber includes all dietary components that cannot be absorbed in the small intestine and can enter the large intestine, mainly various carbohydrates other than absorbable starch, including cellulose, hemicelluloses, various vegetable jellies and microbial jellies, and that absorbs water in the digestive system. It is the essential substance for healthy diet. The fiber can clean the wall of digestive tube and enhance digestive function, dilute the cancerogenic substances and toxic substances in food and accelerate their removal, protect the fragile digestive tract, and prevent colon cancer.
From this definition, we can see that the key to being selected is whether the dietary fiber can be digested and absorbed in the small intestine and whether it can enter the large intestine. And whether it stuffs in chink between teeth and stimulates the throat are not the judgment criteria of dietary fiber. Therefore, a food that seems to contain ribs is not always a high-fiber food; a food without ribs that won’t stimulate the throat does not necessarily mean its fiber content is low.
Then, what is the rib in vegetables? The dietitian of SAMLY ETIT explains that it is the vascular tissue of plants, i.e. the “blood vessel” system of plants. Through these flexible tubes, plants transport the nutrients absorbed by the root system to the upper part and transport the nutrients synthesized by the leaves to the lower part.
However, these ribs do not mean high content of fiber. For example, Chinese cabbage has ribs, but most parts without ribs contain low level of fiber, with the average fiber content of only 0.8%. Some foods without ribs do not necessarily contain low level of fiber and may even contain high level. For example, various fresh beans and fresh pods are high-fiber foods. The green soy bean becomes soft after it is cooked, but that in no way hinders it from becoming the fiber champion (content of dietary fiber: 4.0%) in vegetables. The fresh broad bean (content of dietary fiber: 3.1%) and fresh pea (3.0%) are fine and smooth, and the long bean (1.5%) is crispy, but their fiber content is really much higher than that of celery sticks (1.2%). The rumored super high-fiber Chinese chives have a fiber content of 1.4% only.
“High-fiber” biscuit puts on weight instead
Dietary fibers are divided into insoluble fibers and soluble fibers. Insoluble fibers are usually thought to be somewhat “coarse” and make us be afraid of difficulty when we eat it. However, it is not hard to change this feeling. Insoluble fibers like oil. No matter how coarse the food is and how high a content of fiber it contains, as long as it has been braised or soaked with oil, it will become soft and won’t stimulate the throat at all.
Among the various kinds of grease, the semi-solid grease rich in saturated fat has a better effect than the unsaturated liquid grease. Therefore, high-fiber foods “like meat”. The southerners stew preserved vegetables with streaky pork, and the northerners make bun with fat meat stuffing and potherb mustard – these have the same meaning. For example, high-fiber whole-grain biscuit has been added with large amounts of saturated fat, so it is very easy to eat.
However, if you pursue the comfortable feeling of eating high-fiber foods blindly, you tend to be fooled by the merchants. Many biscuits and desserts are claimed to be “high-fiber” or “with bran” and are still crisp and easy to eat. Many women loving beauty think they can lose weight by eating “high-fiber” biscuit, but such product usually contains quite high content of fat, from more than 20% to 30%.
It is advantageous to eat some fibers, but accompanied with so much saturated fat, the advantage has been early submerged by the disadvantage. To rely on the fiber to clean the intestinal tract, please use FRUIT & VEGETABLE DIETARY FIBER to supplement dietary fibers.