What is fiber and what does it do?
Fiber is a substance found in plants. Dietary fiber is found in fruits, vegetables, and grains. It is an important part of a healthy diet.Dietary fiber adds bulk to your diet. Because it makes you feel full faster, it can be helpful in controlling weight. Fiber aids digestion, helps prevent constipation, and is sometimes used for the treatment of diverticulosis, diabetes, and heart disease. However, if you have diverticulitis, some types of fiber can make your symptoms worse.
There are two forms of fiber: soluble and insoluble.
Soluble fiber attracts water and turns to gel during digestion. This slows digestion. Soluble fiber is found in oat bran, barley, nuts, seeds, beans, lentils, peas, and some fruits and vegetables. Soluble fiber has been scientifically proven to lower cholesterol, which can help prevent heart disease.
Insoluble fiber is found in foods such as wheat bran, vegetables, and whole grains. It appears to speed the passage of foods through the stomach and intestines and adds bulk to the stool.
You should eat 20 to 35 grams of fiber a day. To get more into your diet, eat different types of foods, such as fruits, vegetables, and grains.
Vegetables, Legumes, and Nuts
Vegetables are a major source of fiber:
- Lettuce, Swiss chard, raw carrots, and spinach
- Tender cooked vegetables, such as asparagus, beets, mushrooms, turnips, and pumpkin
- Broccoli, artichokes, squashes, sweet potatoes, and string beans
- Vegetable juices
You can also get more fiber by eating:
- Legumes, such as lentils, black beans, split peas, kidney beans, lima beans, and chickpeas
- Sunflower seeds, almonds, pistachios nuts, and pecans
Fruits are another good source of fiber:
- Apples and bananas
- Peaches and pears
- Tangerines, prunes, and berries
- Figs and other dried fruits
Grains are another important source of dietary fiber:
- Hot cereals, such as oatmeal, farina, and Cream of Wheat
- Whole-grain breads (whole wheat or whole rye)
- Brown rice
- High-fiber cereals (such as bran, shredded wheat, Grape Nuts, Ry Krisp, and puffed wheat)
- Whole-grain pastas
Peeling can reduce the amount of fiber in fruits and vegetables. Eating fiber-containing food is beneficial, whether it is cooked or raw.
Eating a large amount of fiber in a short period of time can cause intestinal gas (flatulence), bloating, and abdominal cramps. This usually goes away once the natural bacteria in the digestive system get used to the increase in fiber in the diet. Adding fiber gradually to the diet, instead of all at one time, can help reduce gas or diarrhea.
Too much fiber may interfere with the absorption of minerals such as iron, zinc, magnesium, and calcium. However, this effect usually does not cause too much concern because high-fiber foods are typically rich in minerals.
The recommendation for older children, adolescents, and adults is 20 – 35 grams per day. Younger children will not be able to eat enough calories to achieve this, but it is a good idea to introduce whole grains, fresh fruits, and other high-fiber foods. Add fiber gradually over a period of a few weeks to avoid abdominal discomfort. Water aids the passage of fiber through the digestive system. Drink plenty of fluids (approximately 8 glasses of water or noncaloric fluid a day).