There are plenty of reasons to eat more high-fiber foods. They can help you control your weight, reduce cholesterol levels, and help prevent type 2 diabetes.
There are two types of fiber: soluble fiber (which dissolves in water) and insoluble fiber (which absorbs large amounts of water). Both are important for disease prevention. Most plant foods contain some of each, but usually one type predominates. Soluble fiber is found in legumes, barley, oats and fruits. Wheat and other whole grains and some vegetables contain mostly insoluble fiber.
Studies show that individuals who consume fiber-rich diets feel less hungry between meals, get full more quickly during meals, and tend to consume fewer calories throughout the day. Both soluble and insoluble fiber contribute to weight control. Soluble fiber forms a gel around food particles, slowing their passage through the stomach and delaying hunger signals to the brain. Insoluble fiber supplies bulk by absorbing water in the digestive tract, which contributes to feelings of fullness and helps discourage overeating.
Studies also suggest that an increase of 5 to 10 grams per day in soluble fiber intake—two to four extra servings of fruits and vegetables a day—can reduce cholesterol levels by about 5 percent. Other studies show that soluble fiber intake directly lowers the risk of heart attacks. Researchers have reported that a low-fat diet coupled with a dietary fiber intake of more than 30 g can help prevent type 2 diabetes. Cereals made from whole grains are especially effective. Fiber slows the absorption of glucose from the intestine and lessens the rise in blood glucose that follows ingestion of carbohydrates.
How to eat more high-fiber foods
Here are six ways to add fiber to your diet.
1. Focus on beans, peas, vegetables, fruits, whole grains and nuts. The goal is to consume 38 g per day if you’re a man or 25 g per day if you’re a woman. Americans today eat only about 15 g of fiber each day. You don’t need to count fiber grams if you eat the recommended daily amounts of fruits, vegetables and whole grains. If you have type 2 diabetes, ask your health-care provider if you should eat even more fiber (particularly soluble fiber).
2. Eat whole grains. Boost your whole grain intake by replacing refined grain products—white bread, white flour, white rice and white pasta—with whole grains. Less than 5 percent of Americans eat the minimum recommended amount, which is 3 ounces per day. When you eat refined grains, make sure they are enriched. To get insoluble fiber, you must consume the bran (the outer coating of the grain) that is removed in the processing of many grains—in particular, wheat milled for flour. Good sources of insoluble fiber include whole-grain cereals; whole-wheat bread, crackers, and pasta; brown rice; and foods made with rye, bulgur or wheat berries. When selecting breads and cereals, look for the words “whole” or “whole grain” as the first ingredient. Keep in mind that whole grains vary in fiber content, so check the Nutrition Facts label to make the best choice. Whole grain should be the first or second ingredient (after water). Vegetables such as broccoli, carrots and potatoes with their skins are also good sources of insoluble fiber.
3. Keep the skin on. Eat oats, oatmeal, barley, dry beans and peas, citrus fruits, and apples and pears with their skins for soluble fiber.
4. Increase intake gradually. A sudden increase of dietary fiber may cause bloating or gas pains.
5. Drink enough fluids. Insoluble fiber needs fluid to be effective.
6. Do not go overboard. A very high intake can interfere with the absorption of some vitamins and minerals.