Fibre: 7 most-asked questions

Eating more fibre is one of the easiest ways to make your diet more healthy and help you if you need to shed a little weight. In case you're hesitating, here's 7 of the most-asked questions I get on fibre - from adapting your favourite recipes, types of bran, wind, irritable bowel disease, to fibre supplements and powders to help alleviate constipation.

Q1. Will fibre help me lose weight?

If you're struggling to lose weight, simply eat more fibre. High-fibre foods such as grainy bread, bran cereals, vegetables and brown rice, require chewing, fill the stomach and the intestines, and take longer to eat. So fibre helps you feel fuller on fewer kilojoules (Calories) and can reduce the full number of kilojoules absorbed into the body.

Fibre also acts as a natural brake to overeating. One glass of apple juice has 325 kilojoules (78 Calories) and can be swallowed in three gulps! You would have to munch on two apples to obtain the same kilojoules, which you can't do in a minute!  Take a look at how fibre decreases as you move from a whole food such as an apple to stewed, then processed apple sauce and finally apple juice in this table:

Q2. Can I adapt my favourite recipes?

Quite easily, by substituting high-fibre ingredients. Use wholemeal flour or oatmeal for thickening casseroles and coating foods. Except for light cakes and delicate sauces, they can replace white flour in many recipes. Have bran muffins instead of biscuits. Try quick-cook brown rice instead of white. Offer unsalted mixed nuts before dinner instead of chips. Add cooked or canned beans to your favourite curries or soups.

Q3. Which bran is best - wheat, oat, barley or rice?

Cereal brans are concentrated sources of fibre, being the outer fibrous layers of the grain. All brans are useful, but act in different ways in the body. At over 40 per cent fibre, wheat bran has the highest fibre content and is rich in insoluble fibre. It is the best choice for your bowel. Oat and barley bran contain some 17 per cent fibre, mostly soluble fibre, so they help lower cholesterol. Rice bran, with 26 per cent fibre, lies in between and has a mix of both sorts of fibre.

Q4. Is fibre OK for Irritable Bowel Syndrome (IBS)?

IBS is a common digestive complaint characterised by abdominal pain, bloating, wind, diarrhoea and/or constipation. While high-fibre foods were once routinely prescribed, they may make things worse in a percentage of cases. They're helpful if you're constipated, but avoid specific foods if they cause pain or distension. The best approach is personal trial and error, bearing in mind that food intolerances also may co-exist.

Q5. I've seen fibre tablets advertised for dieters. Do they work?

Taken with water, supplements like methylcellulose, psyllium or guar gum absorb water and swell in the stomach, creating a feeling of fullness. As they create a soft bulky stool, they also act as laxatives and so prevent some kilojoules being fully absorbed. But, while fibre sup¬plements are an easy pre-meal filler, they are not a substitute for food fibre if your diet is ¬deficient, as the quantity of fibre they contain is quite small (generally less than 3 grams per tablet) and they're expensive.

Mini jelly cups containing konjac or glucomannan (a mucilage) were banned because there had been cases where they swelled and blocked the oesophagus (the tube from the mouth to the stomach), almost causing death.

Q6. I have trouble with wind whenever I eat fibre foods, especially beans and corn. What can I do?

Wind is produced by the fermentation of fibre and other undigested carbohydrates (eg oligosaccharides) by bacteria which break them down to gases, notably hydrogen, methane and carbon dioxide. Legumes, certain vegetables (cabbage, cauliflower, broccoli, onions, Jerusalem artichoke), dried fruit and seeds tend to be the culprits.

Problem foods should be introduced into your diet gradually, starting with small portions. If you are cooking beans from scratch, soak them overnight, discard the soaking water and add fresh water for cooking. Digestion enzymes in products such as Beano or De-gas can also help.

Q7. What's in fibre powders that make them work?

Fibre powders, granules and sprinkles usually contain some form of soluble fibre such as psyllium or sterculia (brand names Metamucil, Fybogel, Nucolox, Normafibre and Fibyrax). However the quantity of fibre they provide is quite small (less than 3 grams per dose) and they are expensive. Still they are a convenient and quick way to help overcome constipation and handy when you're travelling.