Fiber is a complex carbohydrate that your body cannot digest. Fiber keeps your digestive system healthy and can help lower cholesterol levels. High fiber intake is also associated with weight control and decreased risk of obesity. While many foods contain some amounts of fiber, foods in certain foods that belong to the grains, fruits, vegetables and protein food groups provide the most significant amounts of fiber.
The grain food group consists of any food made from a cereal grain, which includes wheat, barley, rice, oats and cornmeal. The grain group is further divided into whole grains and refined grains. Whole grains are those that contain the entire grain kernel, which includes the bran, germ and endosperm, and refined grains contain only the endosperm portion of the grain. Because most of the fiber is found in the bran and germ, whole grains are a good source of fiber, whereas refined grains generally contain only small amounts of fiber. For example, whole-wheat spaghetti provides 2.7 g of fiber per 1/2-cup serving, whereas white spaghetti provides 0.9 g per serving. Whole-wheat bread provides 1.5 g of fiber per slice, and white bread provides 0.6 g of fiber per slice. To meet your fiber needs, most of your grain intake should be in the form of whole grains, such as whole-wheat bread, brown rice, whole-wheat pasta, oats, bran and popcorn.
Foods that belong to the fruit food group are also a significant source of fiber. Raspberries contain 3.3 g of fiber per cup, and strawberries contain 2.8 g per 1.25 cups. A large pear offers 5.8 g of fiber, and a small apple provides 2.8 of fiber. To optimize your fiber intake, choose fresh, whole fruits rather than canned or processed fruit cocktails. Leave the skin on fruits like apples, pears and peaches, since much of the fiber content is contained in the skin.
Vegetables are also a significant source of fiber in the diet. The vegetable food group is divided into five subgroups, which include dark leafy green vegetables, orange vegetables, starchy vegetables, dry beans and peas and other vegetables. Although some groups provide more fiber than others, most of the vegetables in all of these groups contain some fiber. The most significant amount of fiber comes from the dry beans and peas group. A 1/2-cup serving of kidney beans provides 7.9 g of fiber, and 1/2 cup of navy beans offers 6.5 g. Black beans provide 6.1 g of fiber per 1/2-cup serving.
Because beans are a significant source of protein as well as fiber, dry beans and peas belong to both the vegetable food group and the protein food group. Other foods that belong to the protein group, such as meat, poultry and eggs, do not provide significant amounts of fiber.