High-fiber diet

Fiber is a material that gives stability and structure to foods derived from plants. Fiber is what holds an apple in its firm, round shape. It makes the stems of plants such as spinach and kale stand up instead of fall on the ground. What makes dietary fiber different from other foods is that humans can't digest fiber. Instead, it's eliminated through the bowels. Dietary fiber makes passing stools easier because it adds bulk to each bowel movement, holds water, and therefore softens the stool.


Types of fiber
Dietary fiber is found only in plants. There are two types of fiber: soluble and insoluble.
Soluble fiber dissolves in water to become gummy or sticky. This type of fiber pulls fat from the bloodstream into the intestines and encourages its removal from the body. Often added to foods to improve texture and consistency, soluble fiber is found in oats, dried beans, fruits and vegetables.

Insoluble fiber holds water but can't dissolve in water. This type of fiber pulls water into the intestines and helps keep you "regular." Insoluble fiber is found in whole-wheat products, bran cereal, vegetables and fruits.

Most foods of plant origin contain both soluble and insoluble dietary fiber. Although over-the-counter fiber supplements are available, food sources are superior because they contain a variety of nutrients and health protective substances.


Food sources of fiber
Food is the best source of dietary fiber. As a general rule for healthy adults, dietitians recommend eating 20 to 35 grams of fiber each day. A new report issued by the National Academies of Science Institute of Medicine recommends daily intakes of fiber by age and sex. The recommendations are as follows:
Adults age 50 and younger

Men: 38 grams
Women: 25 grams
Adults older than 50

Men: 30 grams
Women: 21 grams
Fruits, vegetables, legumes, whole grains, nuts and seeds are all high in fiber. Try to include six to 11 servings of breads, cereals, rice and/or pasta (emphasizing whole grains); three to five servings of vegetables; and two to four servings of fruit each day.

Approximate fiber content
Bran flakes, ¾ cup 5.0 grams
Raisin bran, ¾ cup 5.0 grams
Wheat germ, 1 tablespoon 1.0 gram
Oatmeal, cooked, ¾ cup 3.0 grams
Whole-wheat bread, 1 slice 2.0 grams
Rice, brown, ½ cup 2.0 grams
Apple with peel 4.0 grams
Strawberries, 1 cup 4.0 grams
Prunes, dried, 3 2.0 grams
Orange, 1 medium 3.0 grams
Banana, 1 medium 2.0 grams
Orange juice, ¾ cup 0.5 gram
Peas, green, ½ cup 2.0 grams
Potato with skin 4.0 grams
Brussels sprouts, ½ cup 3.0 grams
Carrots, 1 medium 2.0 grams
Broccoli, ½ cup 2.0 grams
Tomato, 1 medium 2.0 grams
Baked beans, ½ cup 7.0 grams
Kidney beans, ½ cup 8.0 grams
Lentils, ½ cup 8.0 grams
Peanuts, ¼ cup 3.0 grams
Sunflower seeds, ¼ cup 2.0 grams
Popcorn, 1 cup 1.0 gram



Advantages of fiber
Insoluble fiber decreases constipation and promotes bowel regularity.

Insoluble fiber decreases the risk of hemorrhoids (stretched and swollen veins in the anus or lower rectum).

Insoluble fiber was traditionally believed to decrease the risk of colon cancer by emptying the intestinal tract of cancer-causing waste byproducts. Although it's unclear from recent studies whether dietary fiber itself decreases cancer risk, eating plant-based foods (which are naturally high in fiber) has been proven to be cancer-protective. Therefore, the American Cancer Society and other health experts continue to recommend eating foods that are high in dietary fiber.

Soluble fiber helps prevent heart disease by lowering cholesterol.

Soluble fiber may decrease the need for insulin in people who have diabetes.

Both types of fiber may help control weight because they make you feel full longer.

Both types of fiber may decrease the risk of diverticulosis (diverticula -- small, protruding pouches -- in the colon without inflammation or symptoms).

Disadvantages of fiber
Fiber can produce gas and bloating, especially if you increase fiber intake too quickly. Consuming more than 50 grams of fiber a day may cause loss of zinc, iron, selenium, copper, magnesium and calcium.

Recommendations
To reduce gas and bloating, increase the amount of fiber in your diet slowly. Because water helps fiber move through the digestive tract, drink six to eight glasses of water a day. To get a head start on dietary fiber intake, start each day with a bowl of bran cereal topped with sliced strawberries or another fruit. Instead of white flour, use the whole-grain variety. You may also want to add small amounts of unprocessed bran to baked goods (such as muffin batter and quick bread). For snacks, eat fresh fruit or whole-grain crackers. Try whole grains such as brown rice, bulgur, whole wheat pasta and barley.

Fiber supplements
Although the best source of dietary fiber is food, sometimes a fiber supplement is necessary. If your doctor recommends a fiber supplement, keep the following precautions in mind.
Carefully follow the directions printed on the package.
Take supplements shortly after preparation. Those containing psyllium thicken quickly, making them difficult to drink.
Some supplements cause fullness, so take them before meals if you're overweight or after meals if you're underweight.
Drink 8 ounces of water or juice with every dose.
If you have diabetes and take a fiber supplement that contains sugar, be sure to work it into your diet plan.
If you're on a sodium-restricted diet, make sure you buy a sodium-free supplement.
Although rare, allergic reactions to psyllium have been reported. Contact your doctor if you suspect an allergic reaction to a fiber supplement.
Do not give fiber supplements to an infant or young child without consulting his or her doctor.

Senior-specific information
As you age, physical activity often decreases and the use of medications often increases -- both factors that may contribute to constipation. Increasing the amount of fiber and water in your diet may lessen symptoms. However, for older people who may be underweight or malnourished, a high-fiber diet may not provide enough calories or protein. Consult your doctor about your particular dietary needs.