Dietary fiber
Soluble and insoluble fiber
The fiber is divided into soluble and insoluble, and performs numerous functions; between these:
- It gives a sense of satiety
- Regulates intestinal peristalsis and promotes the systematic evacuation of feces
- Removes waste from the intestine
- It modulates / slows down the absorption of fats and sugars
- Limit cholesterol absorption
- Reduces glycemic and insulin surge
- Partially feeds the intestinal bacterial flora
What is that
A diet low in fiber reduces the fecal volume and hinders the physiological (nervous) process of triggering peristaltic segmentation and advancement contractions.
On the other hand, despite the collective tendency to eat POCA fiber compared to the recommendations (which suggest about 30g / day), in certain "pathological" cases it is necessary to limit it drastically to reduce disorders or undesired symptoms; this diet is called a low fiber diet or low residue diet .
For whom it is indicated
The function of low-fiber or low-residue diet is to reduce the laxative effect on the digestive tract; the cases in which it may be necessary to apply it are mainly:
- Irritable bowel syndrome
- Colitis (inflammatory, infectious, chemical, etc.)
- Intolerances and allergies
- Pharmacological therapies
- Radioactive therapy
- Intestinal resection (due to cancer, Crohn's disease or ulcerative colitis)
- Preparations for endoscopic diagnostic investigations of the itestinal tract (eg colonoscopy)
- Etc.
Logically, when normal physical conditions are restored (if possible), the low residue diet should be interrupted by replenishing the recommended dietary fiber share.
What to eat
In practical terms, the low-fiber or low-residue diet is a nutritional scheme poor in fruit, vegetables, cereals and legumes which, if present, MUST be processed / refined so as to at least eliminate the typical external coating (peel, pericarp or other fibrous integuments, etc.) notoriously rich in this element (in essence it is necessary to avoid whole grains).
Although not correlated with the intake of dietary fiber, even milk and dairy products (or the foods that contain them) may be limited / interrupted in the administration of the low residue diet; this choice is not accidental and is based on the concept that, in most intestinal suffering, the lactase enzymes present on the mucosa are drastically reduced, causing the bacterial fermentation of lactose and the consequent annexed symptomatology (see food intolerance to lactose).
To properly manage the low residual diet it is advisable:
- Carefully scrutinize food labels
- Make sure that each food portion does not add more than 1g of total fiber.
See an example of low residue diet »
Cooking methods
Cooking methods for low-fiber or low-residue diets are moderate and non-violent; they should never over-trigger the Maillard reaction and / or the production of toxic / irritating molecules for the intestinal mucosa (acrylamide, acrolein, polycyclic aromatic hydrocarbons, etc.). Recommended: boiling, steaming, microwave cooking and pressure cooking; in the eventualities, even slow stewing. Grilling, frying, roasting and baking at very high temperatures without a lid are NOT RECOMMENDED. Another useful suggestion is to avoid or not to exceed with spices, such as pepper, chilli, curry, coriander, cumin, etc.
Supplements
- In the event that the low residue diet causes an excessively "stringent" effect on the faeces, it is advisable first of all to increase the water supply (compromise for the elimination of fruit and vegetables) and, only later, to reinsert the fiber little by little.
- The low-fiber or low-residue diet causes a minor reduction of a good portion of mineral salts (magnesium, potassium, etc.), vitamin C, B-carotene and vitamin K; it is therefore advisable to evaluate together with the doctor the possibility of using a good dietary supplement to maintain sufficient nutritional intake of these nutrients.
