Nutritionist-Dietitians' Association of the Philippines

Dietary fiber is the class of compounds consisting of nondigestible polysaccharides found in plant cell walls. Bacteria in the large intestine partly digest fiber through fermentation.  Fiber is not found in foods of animal origin ( meats, dairy products).

Types of Fiber
Soluble or viscous fibers are found mainly within plant cells. They form a gel which slows both stomach emptying  and the absorption of sugars from the intestines. They are more concentrated in oats, barley, soybeans, dried beans and peas, psyllium, flax seed and citrus fruit.They lower blood cholesterol by binding bile acids and excreting them.  More cholesterol must then be broken down to supply bile acids for emulsification of dietary fats. Weight control is also aided by the feeling of fullness provided by the slow transit in the intestines.
Insoluble or nonviscous fibers are the structural parts of plant cell walls.  They have high water-binding capacity which reduces transit time in the large bowel. Reduced transit time promotes regularity and minimizes risk of colon cancer by decreasing the time that coloncytes are exposed to potentially carcinogenic wastes. Best food sources are wheat bran, corn bran, rice bran, whole grain cereals and breads, beans and peas, seeds, and the skins of fruits and vegetables.

Which one has the highest fiber content?

EAT THIS  !	NOT THIS………

E×cessive dressing, croutons, and cheese, a standard Chicken Caesar salad can total more than 1,000 calories and 90 grams of fat.  Request no dressing ( save up to 475 calories) and lose the croutons (another 70 calories of savings). Instead, toss with one or two teaspoons of olive oil and unlimited vinegar. This lighter version practically slashes the calories in half.

Fiber Myths

Low carbohydrates and not high fiber  makes one thin.
There is a lot of confusion between carbohydrates and fiber.  Carbohydrates are the main contributors of energy to the body ( the others are protein and fat). Carbohydrates are found not only in bread, rice, pasta, and sugar, but also in fruits and vegetables, whole grains, beans, nuts, and seeds , good sources of fiber .   Some experts refer to fiber as the “ forgotten carbohydrate.”   Few are aware of the  vital role that dietary fibre can play in the prevention of weight gain and promotion of weight loss.  Researchers believe that high fiber foods linger longer in the stomach, giving a sensation of sustained fullness. They offer fewer calories for the same volume of food.  They require more chewing , giving the body time to feel full and stop eating, reducing the risk of over-consumption. Eating less carbohydrate may mean less fiber and possibly increased hunger.  

Too much fiber is harmful.
Take it slow when increasing dietary fiber. Add just a few grams at a time to allow the intestinal tract to adjust; otherwise, abdominal cramps, gas, bloating, and diarrhea or constipation may result. Other ways to help minimize these effects: drink at least 2 liters (8 cups) of fluid daily and use fresh water to cook dried beans and discard the water in which they were soaked. Excessive intake of dietary fiber has been linked with reduced absorption of vitamins, minerals, proteins, and calories. However, it is unlikely that healthy adults who consume fiber in amounts within the recommended ranges will have problems with nutrient absorption.

Frequently Asked  Questions

How much fiber should I eat?
The recommended intake for total fiber for adults up to 50 years of age is set at 25 grams per day for women and 38 grams for men. For those over 50, the recommended intake is 21 grams for women and 30 grams for men.

Can we get fiber from a pill?
Fiber supplements are often recommended by doctors to patients who have chronic digestive disorders, such as irritable bowel or chronic constipation. Pills also help meet the recommended daily fiber intake.   There is no strong evidence that long term use of soluble fiber supplements such as Metamucil (psyllium fiber)  or Citrucel ( methylcellulose), acacia fiber, benefiber are harmful.  However, they can decrease the absorption of nutrients and certain medications, such as aspirin, warfarin and carbamazepine.  Consulting one’s physician before taking supplements is very important. 

How can I increase the fiber content of my diet?
Tips to get daily fiber recommendation are: 

• Eat 5 servings of fruits and vegetables each day , preferably fresh whole rather than liquid or juice.
• Take 7 servings of whole grains and beans in the form of whole grain bread or pasta, brown/ wild rice,  oatmeal, or bulgur.
• Cut back on pastries and choose fruit for dessert and snacks.
• Reduce meat servings and add more vegetables, fruits, whole grains and beans to every meal.  Add chopped vegetables to soups and sauces.
• Savor the skin of fruits and vegetables.  It gives a bonus of other nutrients.
• Go nuts.  Jazz up salads, vegetables, snacks, desserts, baked products with peanuts, cashew, almonds, crushed bran cereal.  
• Take high fiber breakfast cereals . 
• Skip the chips; go for popcorn, whole-wheat pretzels, oat crackers.
• Add bean, peas, lentils to canned soup/ salad.
• Root vegetables and tubers are rich in fiber too!    

What is the difference between inulin and psyllium?
Both inulin and psyllium are natural, plant-based starches. Inulin is sometimes called a "prebiotic" because it stimulates  growth of good bacteria in the colon.  It is now increasingly added to processed foods  like baked products and beverages not only to improve stability, taste, and texture but to increase fiber content. Psylllium is a fiber supplement that contains calories and can cause gas.  So too with inulin for some who may not know they are consuming too much of it.

What is the difference between white bread and whole bread?
White breads come from white flour,  processed by  milling and bleaching that leaves most of the vitamins, minerals and especially fiber out.  Then, breadmakers go to the trouble of adding certain vitamins and minerals back in to the refined flour, because the FDA requires them to; hence,  one sees the words “enriched” or “fortified.”   Whole grain products are darker, chewier and more flavorful, because all three layers : bran, germ, endosperm, come together to make the flour.
Their fiber content can be as much as four times that of refined white flour.

Here are fiber misconceptions to watch out:  (AICR e.Newsletter )
Don’t think that the number of grains (five, six, seven, twelve or even the vague catch-all “multi-”) says anything about whether those grains have been refined or not.
Don’t rely solely on the package’s health claims.  A “Whole Grain Stamp” or other form of identification can be helpful, but there’s still some disagreement among food manufacturers and the FDA on how to categorize whole-grain products. Do head straight for the ingredients list.  Look at the first ingredient that’s what to go by.  On breads, pastas, rice and cereal, look for the words “whole” or “100 % whole” before the name of the grain. 

What is the difference between white bread and whole bread?
"Whole grains like brown rice, wheat, corn, oatmeal, rye are those cereal grains that retain the bran and germ, along with the endosperm.   They are naturally high in fiber, vitamins, minerals, and  antioxidant phytonutrients.  Whole wheat refers to the flour obtained when the wheat grain is ground or mashed to make bread. Unrefined white flour contains only the endosperm.

References/Links

Hyman, Mark.  Ultrametabolism.  Scribner. NY. 2006.
Asian Food Information Center .www.afic.org
SMART Nutrition 101 www.nutrition.gov.
ibdcrohns.about.com
American Institute of Cancer Research AICE e-Newsletter. Aug. 2006.
www.diffen.com