7:51 PM
Fiber is made up of non-starch polysaccharides, such as cellulose, dextrins, inulin, lignin, chitins, pectins, beta-glucans, waxes and oligosaccharides. The word fiber is misleading, because many types of dietary fibers are not fibers at all.
There are two broad types of fiber, soluble and insoluble. Soluble dissolves in water, while insoluble does not. No fiber can be digested. However, soluble fiber changes as it goes through the digestive tract, where it is fermented by bacteria. Soluble fiber absorbs water, and as it does so becomes gelatinous. Insoluble fiber goes through the digestive tract without changing its forms.
Dietary fiber foods are generally divided into predominantly soluble or insoluble. Both types of fiber are present in all plant foods, but rarely in equal proportions.
The fiber make-up of some foods
Cereal grains - ½ cup cooked
| Soluble | Insoluble | |
| Barley | 1g | 4g |
| Oatmeal | 1g | 2g |
| Oatbran | 1g | 3g |
Seeds
| Soluble | Insoluble | |
| Psyllium seeds ground (1 Tbsp) | 5g | 6g |
Fruit (1 medium fruit)
| Soluble | Insoluble | |
| Apple | 1g | 4g |
| Banana | 1g | 3g |
| Blackberries (½ cup) | 1g | 4g |
| Citrus Fruit (orange, grapefruit) | 2g | 2-3g |
| Nectarine | 1g | 2g |
| Peach | 1g | 2g |
| Pear | 2g | 4g |
| Plum | 1g | 1.5g |
| Prunes (¼ cup) | 1.5g | 3g |
Legumes (½ cup cooked)
| Soluble | Insoluble | |
| Black Beans | 2g | 5.5g |
| Kidney Beans | 3g | 6g |
| Lima Beans | 3.5g | 6.5g |
| Navy Beans | 2g | 6g |
| Northern Beans | 1.5g | 5.5g |
| Pinto Beans | 2g | 7g |
| Lentils (yellow, green, orange) | 1g | 8g |
| Chick Peas | 1g | 6g |
| Black eyed Peas | 1g | 5.5g |
Vegetables (½ cup cooked)
| Soluble | Insoluble | |
| Broccoli | 1g | 1.5g |
| Brussels Sprouts | 3g | 4.5g |
| Carrots | 1g | 2.5g |
Soluble fiber:
Soluble fiber is broken down by enzyme-producing bacteria present in the colon to produce energy and gas and bulky stools. This fiber forms a gel-like substance which can bind to other substances in the gut. It also has the extra benefits of lowering cholesterol levels and slowing down the entry of glucose into the blood, thereby improving blood sugar control.- It reduces cholesterol, especially levels of LDL (bad cholesterol)
- It regulates sugar intake, this is especially useful for people with diabetes and metabolic syndrome
Food sources of soluble fiber:
- Kidney beans
- Pinto beans
- Brussels sprouts
- Broccoli
- Spinach
- Zucchini
- Fruits (raw)
- Apple
- Orange
- Grapefruit
- Grapes
- Prunes
- Grains Oatmeal
- Whole-wheat bread
- Promotes regular bowel movements and prevents constipation
- Speeds up the elimination of toxic waste through the colon
- By keeping an optimal pH in the intestines, insoluble fiber helps prevent microbes from producing substances which can lead to colorectal cancer
Insoluble fiber:
Insoluble fiber is less easily broken down by bacteria in the colon, but holds water very effectively (up to 15 times its weight in water) thus contributing to an increase in stool weight. It is this fiber that is often referred to as ‘nature’s broom’ and is thought to have many protective effects on the gut. Insoluble fibers have many functions, including moving bulk through the digestive tract, and controlling pH (acidity) levels in the intestines.Benefits of insoluble fiber:
Food sources of insoluble fiber:
- Vegetables - especially dark green leafy ones
- Root vegetable skins
- Fruit skins
- Whole wheat products, wheat bran
- Corn bran
- Nuts and seeds
Fiber is good for you
Eating fiber has many benefits for your health. The consumption of soluble fiber has been shown to protect you from developing heart disease by reducing your cholesterol levels. The consumption of insoluble fiber reduces your risk of developing constipation, colitis, colon cancer, and hemorrhoids.
People with diabetes who consume a lot of fiber tend to need less insulin than those whose fiber intake is low.
Most foods which are high in fiber are also very good for you for other reasons. Take, for example, fruit and vegetables and whole grains, they are high in fiber but also rich in vitamins and other essential nutrients. In other words, if you seek a high-fiber diet, not only will you be protecting your health because of your fiber intake, but also because you will consume other essential nutrients.
A high-fiber intake can significantly contribute towards your body-weight control. Fiber fills you up without adding calories (fiber calories are not absorbed by your body) - this can help treat or prevent overweight/obesity. Many overweight people experience several months of relatively ‘effortless’ weight loss if they make a major change to a regime of ‘high fiber’ with lots of fruit and non-starchy vegetables. They are also recommended to take more exercise at the same time. Weight loss achieved in this way can lower blood pressure, lead to better sugar control, and reduce general levels of inflammation in arteries and joints.
How much fiber should we
eat?
Ideally, adults should aim for an intake of more than 18 grams a day. Eating a lot more fruit and bulky vegetables and grains etc. however, does have consequences. You not only will need to adapt your tastes and cooking, you will notice other effects!
A word of caution is relevant. If you would like to increase your fiber intake from a relatively low level, it is best to do it gradually. This is because a sudden increase may produce wind, bloating and stomach cramps - and changes in frequency of bowel movements.
You should drink enough fluid:
Without fluid, dietary fiber cannot do its job. Insoluble fiber, in particular, acts like sponge absorbing water, increasing stool weight and size, thus putting pressure on the bowel wall and facilitating the movement of the stool. Without fluid this fiber is pointless and will only result in constipation. Try to drink at least 3-4 pints (8-10 cups) of fluid per day. Suitable fluids include non-caffeine and non-alcohol based drinks like water, fruit teas, well-diluted fruit juices and fruit squashes.
