High Fiber Vegetables & Whole Grain Foods

Dietary fiber has had a lot of good press over the years, said to prevent everything from constipation to cancer. Though it is not physically digested, it can be metabolized by bacteria in the large bowel. Some of the health claims for fiber have good foundations, but others have been over-stated at best, and hypothetical at worst. That said, fiber-rich foods, such as vegetables and whole grains, are generally good for the aid of digestion, either speeding things up or slowing them down. The benefits of speeding things up include preventing constipation. The benefits of slowing down digestion include making you feel fuller for longer, which can lead to weight loss.

Types of Fiber

There are two basic forms of plant based fiber. These are called soluble and insoluble, and each has a different effect on the digestive process. Soluble fiber absorbs water and other fluids like a sponge, and turns into a gel-like substance in the gut. This has the effect of slowing down digestion, which can make you feel fuller for longer. Insoluble fiber speeds up the digestive process and adds bulk to bowel movements.

Specific Plant Fibers

Water soluble fibers include pectin and gum, which are inside plant cells. These are the types of fiber that make you feel fuller. Good sources of water soluble fibers include oat bran and most vegetables. Insoluble fibers, which are found in the walls of the plant cell, include cellulose, hemicellolose and lignen. Most insoluble fiber comes from wheat bran, whole grains and some vegetables and beans. These are the types of fiber that speed up digestion in the lower gut.

Health Benefits

The type of fiber found in whole grain products makes digestive waste, or stools, softer and bulkier, which will speed up the elimination process. This can help constipation, hemorrhoids and diverticulosis, a condition in which small pouches form in the intestinal wall, causing pain and blockages.The British Heart Foundation fact sheet on fiber and cholesterol says that studies are inconclusive, because those with a higher fiber intake also tend to have a lower fat intake and better lifestyle habits. Similarly, a 2005 study by Yikyung Park, et al., published in "The Journal of the American Medical Association" concluded that a high fiber diet, despite findings from previous studies, was not associated with a lowered risk of bowel cancer. The American Diabetes Association says that eating a fiber rich diet "may" help older men from getting Type 2 diabetes. Because certain fibers keep you fuller for longer, you may decrease your caloric intake, so high fiber diets can aid weight loss.

How Much

Most Americans consume far less than the recommended daily intake of fiber. The most recent guidelines, from the 2005 Dietary Guidelines for Americans, suggests 14 g of fiber per 1000 calories. There are different recommendations according to age and sex. Because children have smaller stomachs, the Dietary Reference Intake of fiber for 4- to 8-year-olds is 25 g per day. Teenage boys should aim for 38 g per day, whereas teenage girls should try to get 26 g per day. The highest recommended intake is for men between the ages of 19 and 50, at 38 g per day. These relatively high figures, compared to the average American fiber intake of 14 g per day, may seem daunting, but the trick is to change your diet slowly, to avoid bloating and flatulence.

High Fiber Foods

Foods considered high in fiber include 5 g or more per serving. One half cup of All Bran cereal provides 8.8 g of fiber. For vegetables, one cup of baked beans contains 4 g of fiber; one cup of cooked split peas has a whopping 18.2 g of fiber; and one cup of cooked lentils contain 15.6 g of fiber. Other good, but less high sources of fiber include cooked green beans, canned beets, baked potatoes, sweet potatoes and most of the winter squashes. For cereals and grains, good, fiber filling sources include Shredded Wheat, oatmeal, brown rice, Bulgar wheat and buckwheat. If all that seems too stodgy, you can increase your fiber intake with salads and lightly cooked vegetables, and snack on raw vegetables and fruit.