Why should you eat high fibre foods? –
Written by Dr Harold Gunatillake Health writer

Carbs with the high GI (glycaemic index), when digested in your gut, elevates your blood sugar. We call this, ”spiking blood sugar”. If your pancreas is making enough insulin there is no issue, the blood sugar level will come down to fasting levels within about two hours.
If you do not secrete sufficient insulin, the absorbed sugar will remain in your blood and elevate your blood sugar level. This is exactly what happens in diabetes. Non-diabetics also shows high blood sugar levels after consuming carbs, but within two hours the level comes down to fasting levels.

‘Glucose tolerance test’ done to check for diabetes is based on this rationale Fibre found in high fibre foods is an indigestible form of carbohydrate and it does not get absorbed but passes through the large bowel as bulk in your stools. In short, it does not matter whether they have a high GI, or not. They lower the blood sugar levels when high GI foods are digested, due to slow absorption.
Remember, the meat and fish you eat veggies and fruits have no fibre and is totally digested and absorbed.
Fibre is mostly found in carbs like the veggies and fruits we eat. Again, some have increased levels of fibre and others have low levels.
Do you know that it is the fibre component in plants that gives the strength to stay upright: it forms the skeleton of the plant?
The fibre in the carbs you consume comes in two varieties, both of which are beneficial especially to diabetics and for those who go on diets to reduce weight.

The two varieties of fibre are- soluble fibre and insoluble fibre.

Soluble fibre is found in high levels in oat bran, legumes like lentils, green vegetables, roots nuts and some fruits.
Insoluble fibre is found in high levels in wheat bran, unprocessed foods like wholemeal bread, brown and red rice, vegetables, seeds and skins of some fruits. Those who suffer from regular constipation should eat foods with high levels of insoluble fibre.
One of the best tubers that contain high insoluble fibre is ‘Kohila’ (Lasia spinose) a marshy herb which grows abundantly in Sri Lankan marshlands. The fibre content is so high that people not used to eating this vegetable get colic due to the increased peristalsis movements of the bowels. The Ayurveda physicians prescribe this herb for those suffering from chronic constipation and haemorrhoids.
Another high fibre food available in Sri Lanka is the unripe banana flowers or fruits (Kehel muwa) in a curry form or stripped and fried (mallung). This treat too can give you colic Insoluble fibre in high levels in food may reduce the risk of bowel cancer. According to Colorado State University Extension, insoluble fiber increases the rate at which waste is removed from the body. This, therefore, reduces the exposure of toxic substances that develop as a by-product of digestion.

People with diabetes should consume at least 25 grams of dietary fibre daily.

Some of the high fibre foods you should eat frequently are:
Non-starchy veggies ( Kale, spinach whole-grain bread, whole-grain or bean pasta, oatmeal, mixed with fresh berries, sliced bananas, avocado fruits, Greek yoghurt, Kale, carrots, sweet potatoes, citreous fruits like oranges, mangoes (high fibre variety,”Kohu Amba)
You should aim at consuming 35 grams of fibre for men and 25 grams in your daily food, but most people do not consume more than 10 grams a day. Become a vegetarian, you’ll consume more fibre.

Soluble fibre mixes with water in the bowel form a gel. Insoluble fibre passes through without changes.

What happens to soluble fibre in the gut?

Our gut has trillions of microbiota. For their health one has to eat pre-biotics and probiotics. The best prebiotics is high fibre containing diets. For the beneficial bacteria to survive in our gut we need to consume meals with high dietary fibre, while the harmful bacteria thrive on sugars and alcohols. So you need to consume more fibre-packed foods, such as leafy greens, oatmeal and whole grain.
You need to eat high fibre vegetarian diet to keep the microbiota happy and healthy. Beneficial bacteria produce higher levels of molecules called short-chain fatty acids which are beneficial for our health. These short –chain fatty acids are produced by certain types of gut bacteria when they break down insoluble fibre in your diet. These molecules play a protective role against different diseases.
So there is evidence that if people do not eat too much meat, and they increase the amounts of fruits, vegetables and legumes containing high dietary fibre are likely to have a healthy community of gut bacteria.
Gut bacteria among meat eaters who consume very little high fibre produce a chemical called Trimethylamine oxide (TMAO) due to the breakdown of animal protein and fat in your meat, eggs and dairy, among others. This compound is found in the urine of meat eaters and not those who eat a high fibre vegetable diet. TMAO seems to cause inflammation of blood vessels, blood clots, ulcerative colitis, Crohn’s disease, irritable bowel syndrome and heart disease.

So the importance of eating high dietary plant foods are stressed and benefits reciprocating from our gut microbes are so beneficial, compared to those people who consume a lot of meat.

Further, consuming high fibre diets slows the absorption of sugar from the digested carbs in your gut, and there are less likely chances of causing glucose spikes in your blood.

If you suffer from chronic constipation you need to consume high fibre foods. The dietary fibres relieve and prevent constipation. Eat plenty of wheat bran, legumes and seeds daily as mentioned earlier.

If you suffer from a diverticular disease of the large bowel from infections and inflammation of the finger-like pouches, you need to eat high fibre dietary foods. Also, such foods reduce the risk of diverticular disease.

Conclusions: The importance and beneficial effects of eating high fibre dietary foods are discussed