Dietary fiber is a group of compounds found in plants that cannot be fully digested in our gut. Fiber-rich foods like fruits, vegetables, and whole grains have consistently been shown to benefit our health and reduce our risk of disease. While the exact mechanism for these benefits is not fully understood, it is believed, at least in part, that it is due to their fiber content. Here we discuss the definition of dietary fiber and the range of health benefits associated with its intake.
Dietary fiber: what they are and how they work
By dietary fiber, we mean all those organic substances that the enzymes of our digestive system are not able to break down and, therefore, digest.
They fall into the category of carbohydrates and are predominantly vegetables in nature, so they are found in foods such as fruits, vegetables, cereals and legumes.
They constitute the “indigestible” part of foods, i.e. substances that are not absorbed by the intestine and that do not have any caloric and nutritional intake, but are fundamental for the main intestinal functions.
According to their structure, they can be distinguished into two categories: soluble and insoluble.
Soluble dietary fiber
As the name suggests, soluble fibers are able to dissolve in water and take the form of a gelatinous and viscous substance.
If for our body they are not digestible, they are instead an excellent source of sustenance for the bacterial flora that populates our intestine and protects it from infections, for this reason, the fibers are also called prebiotics.
Soluble fiber helps to increase the sense of satiety because, being vicious, it slows down the intestinal transit of foods, causing us to eat less.
In addition, it is able to limit the absorption of fats and sugars, so it is a good ally for diets aimed at weight loss.
Insoluble dietary fiber
Insoluble fibers, on the other hand, are not able to dissolve in water but rather absorb it, increasing in volume.
When they are in the intestine they increase the volume of feces, which are softened by water, stimulating intestinal peristalsis and facilitating evacuation.
This not only helps intestinal regularity but also prevents the toxins contained in the stool from being absorbed by the body due to excessive permanence in the colon, helping to ward off infections and much more serious disorders.
What are the groups of dietary fibers found in foods
There are generally four different groups of dietary fibers found in foods:
Non-starchy long-chain carbohydrates are structural parts of most fruits, vegetables, whole grains, legumes, beans, and nuts. They can be found in the form of, for example, cellulose, pectins and glucans. These constitute the largest group of fibers and are found in a variety of concentrations.
Medium-long chain resistant carbohydrates such as fructo-oligosaccharides (FOS) and galacto-oligosaccharides (GOS). These are carbohydrates made up of less than 10 smaller sugar units. GOS is often found in seaweed and FOS is found in vegetables such as chicory, onion and asparagus.
Resistant starch is a form of starch that cannot be digested in the small intestine. It is found in foods such as bananas, potatoes, grains, legumes, and seeds.
Lignin is an exception to the simple definition of fiber, as it is not technically a carbohydrate, but is considered a fiber. Lignin is found in root vegetables such as carrots and turnips, as well as in nuts and seeds.
Vegetable fiber adds volume to the diet; causes a feeling of satiety that can help control weight.
In addition, fiber collaborates closely with the intestinal flora, the set of bacteria that live in the intestine and that are responsible for processing some foods that are difficult to digest, absorb nutrients and form a complex ecosystem that self-regulates and stays in balance. Fiber helps to give consistency to the feces and thus favors intestinal transit. In addition, it reduces the absorption of cholesterol, glucose and bile acids.
A diet low in fiber prolonged over time can trigger problems such as chronic constipation, diverticulosis, colon cancer, irritable bowel syndrome or ulcerative colitis.
the benefits of dietary fiber
The benefits derived from a correct intake of fiber are many, especially if considered in correlation with a correct diet.
Let’s see the most important.
Starting from the mouth, where “the first digestion” begins, foods rich in fiber require greater chewing, so they allow you to activate a useful mechanism to improve the digestive process in the stomach, often underestimated due to the frenetic rhythms of the daily routine.
At the metabolic level, however, one of the best-known benefits is to promote regularity and stimulate intestinal transit, particularly useful for those suffering from constipation and sluggish intestines.
In addition, when the fibers reach the intestinal tract they swell and increase the sense of satiety. The digestive process slows down, and the assimilation of fats and sugars also occurs more slowly.
This allows you to introduce fewer calories and avoid hunger attacks, especially in those who are undergoing a low-calorie regimen.
At the same time, by interfering with the assimilation of lipids and carbohydrates, fiber helps to control disorders such as blood sugar, diabetes, high cholesterol, and coronary artery disease.
Some soluble fibers also undergo a fermentation process once they reach the stomach. This favors the proliferation and development of intestinal bacterial flora, that is, those “good” bacteria that guarantee the health of our intestines and act against infections.
Finally, taking foods rich in fiber helps prevent colon and rectal cancers because they prevent the prolonged permanence of feces, which contain toxins, in this intestinal tract.
How to take fiber and in what quantity?
The best way to introduce fiber into the body is through nutrition, opting for a healthy and balanced diet.
According to experts, the daily requirement of fiber for an adult individual corresponds to 30 grams, but this value can vary according to the build, weight and specific needs of each.
In addition, to improve the effectiveness and benefits, it is advisable to drink a lot and practice regular physical activity.
5 Tips to Increase Your Fiber Intake
Fiber has more than one health benefit, it affects the entire body and mind. So why not opt for a fiber-rich option every day? It’s not complicated:
- choose whole grain products instead of refined grain products
- add vegetables to every meal
- opt for beans and legumes as meat alternatives
- opt for fruit snacks
- snack nuts and seeds between meals
Before you know it, these small choices can turn into habits. Try! Let a diet full of fiber pave the way to a healthier life.