Dietary fiber includes the parts of plant foods that body can't digest or absorb. Instead, it passes relatively intact through stomach, small intestine and colon and out of the body.

Fiber is commonly classified as soluble and insoluble.

Soluble fiber. This type of fiber dissolves in water to form a gel-like material. It can help lower blood cholesterol and glucose levels.

Insoluble fiber. This type of fiber doesn't dissolve in water. It promotes the movement of material through digestive system and increases stool bulk, so it can be of benefit to those who struggle with constipation or irregular stools.

Benefits of a high-fiber diet

A high-fiber diet has many benefits, which include:

Normalizes bowel movements. As fiber passes through the stomach and intestines, it absorbs water, adding bulk to the stool and softening it. This promotes regularity and reduces constipation.

Helps maintain bowel health. A high-fiber diet may lower the risk of developing hemorrhoids and small pouches in colon (diverticular disease).

Irritable bowel syndrome (IBS): Fiber may provide some relief from IBS

Lowers cholesterol levels. Fiber traps cholesterol and drags it out of the body through the digestive system. Soluble fiber, found in oat bran, barley, oranges, apples, carrots, and dried beans, turns into a gel during the digestive process and prevents cholesterol, fat, and sugars from being absorbed by the body

Helps control blood sugar levels. In people with diabetes, fiber — particularly soluble fiber — can slow the absorption of sugar and help improve blood sugar levels. A healthy diet that includes insoluble fiber may also reduce the risk of developing type 2 diabetes.

Aids in achieving healthy weight. High-fiber foods tend to be more filling than low-fiber foods, so you're likely to eat less and stay satisfied longer. And high-fiber foods tend to take longer to eat and to be less "energy dense," which means they have fewer calories for the same volume of food.

Heart health: There is an inverse association between fiber intake and heart attack, and research shows that those eating a high-fiber diet have a 40 percent lower risk of heart disease. The reason behind it might be that high-fiber foods help in reducing blood pressure and inflammation.

Stroke: Researchers have found that for every seven-grams more fiber you consume on a daily basis, your stroke risk is decreased by 7 percent.

  • Skin health: Fiber, particularly psyllium husk, may help move yeast and fungus out of your body, preventing them from being excreted through your skin where they could trigger acne or rashes.
  • Gallstones and kidney stones: A high-fiber diet may reduce the risk of gallstones and kidney stones, likely because of its ability to help regulate blood sugar.

Fiber: Daily recommendations for adults

Age 50 or younger                                                                       

Men: 38 grams                                                                                                           

Women: 25 grams

Age 51 or older

Men: 30 grams

Women: 21 grams 

Your best fiber choices

If you aren't getting enough fiber each day, you may need to boost your intake. Good choices include:

Soluble fiber is found in varying quantities in all plant foods, best sources are:

  • Legumes (peas, soybeans, lupins and other beans)
  • Oats, rye,chia and barley
  • Some fruits like figs, avocados, plums,prunes, berries, ripe bananas, and the skin of apples, quinces, pears and citrus fruits.
  • Certain vegetables such as broccoli, carrots, brinjal, tomato, celery
  • Root tubers and root vegetables such as sweet potatoes and onions (skins of these are sources of insoluble fiber also)
  • Psyllium seed husk (a mucilage soluble fiber) and flax seeds.
  • Nuts with almonds being the highest in dietary fiber

Sources of insoluble fiber include:

  • Whole grains foods
  • Wheat and corn bran
  • Legumes such as beans and peas
  • Nuts and seeds like flaxseeds, sesame seeds.
  • Vegetables such as green beans, cauliflower, celery, cabbage, bell peppers, onions.
  • Some fruits including avocados, and unripe bananas
  • The skins of some fruits and vegetables including kiwifruit, grapes, tomatoes, cucumbers, potato.

High-fiber foods are good for your health. But adding too much fiber too quickly can promote intestinal gas, abdominal bloating and cramping. Increase fiber in your diet gradually over a period of a few weeks. This allows the natural bacteria in your digestive system to adjust to the change.

Also, drink plenty of water. Fiber works best when it absorbs water, making your stool soft and bulky.