Fiber is a nutritional superstar. Not only does fiber help keep you regulated in the bathroom department (always a plus...), but it also reduces the risk of heart disease, cancer, and adult-onset diabetes. What’s more, high-fiber foods enhance weight loss as they require more chewing and stimulate satiety hormones that tell your brain to stop eating.
Found in fruits, vegetables, whole grains, and legumes, fiber is simply the portion of plant foods that humans cannot digest. Most people already know that fiber is part of a healthy diet; however, other facts about fiber—the difference between soluble and insoluble fiber, how to find high-quality sources of fiber, and so on—tend to fall below mainstream radar. Here’s a “roughage” breakdown to get you started toward a healthier, more regulated you.
Insoluble fiber is the coarse, chewy part of a plant that does not dissolve in water. It forms a plant’s structure and can be found in the outside tissues like fruit skins, stringy vegetables, and crunchy whole grains. Insoluble fiber passes through the body largely intact; it soaks up water like a sponge, adding bulk and softness to the stool. This not only prevents constipation, but also speeds the rate at which food goes through your system. Whole-wheat breads, wheat bran, rye, most other whole grains, cabbage, beets, carrots, Brussels sprouts, turnips, cauliflower, and apple skin are all loaded with insoluble fiber.
Soluble fiber, on the other hand, is found inside plant cell walls. It dissolves and thickens in water to form a sticky, gel-like substance. Soluble fiber gives oatmeal its gummy texture and cooked beans their mushy centers. As it passes through the digestive system, soluble fiber binds to dietary cholesterol, helping the body to eliminate it. Soluble fiber slows down digestion in the stomach and intestines and may also increase the uptake of minerals and other nutrients during digestion. Oats (which have the highest proportion of soluble fiber of any grain), oat bran, beans, peas, rice bran, citrus fruits, strawberries, and apple pulp are full of soluble fiber.
Filling up on Fiber
Current nutritional recommendations suggest that adults need 20 to 35 grams of dietary fiber each day. If the idea of eating bowl after bowl of bran makes you groan, take heart. Filling up on fiber is a lot easier than you may think. Below, some quick and easy ways to sneak more fiber into your diet:
- Go for whole grain: Look for bread, cereal, and crackers that are 100 percent whole grain—meaning no refined flour. If the label does not say “100%” check the ingredient list for refined culprits like white flour (usually listed as bleached or unbleached enriched wheat flour), semolina or durum flour, and rice flour. These bad boys don't only contain less fiber; they also generally don't have as many natural vitamins and minerals as their unrefined counterparts.
- When out on the town, choose brown: Include other 100 percent whole grains in your diet, including brown rice, bulgur wheat, oatmeal, barley (including pearled barley), buckwheat, cracked wheat, quinoa, and amaranth. An increasing number of restaurants now offer a choice of brown rice, buckwheat pancakes, and so on. Don't be afraid to ask!
- Eat more beans: Beans offer tons of soluble fiber, plus a lot of plant protein. Include them in soups, stews, and salads, and replace some of your meat-based dishes with high-fiber, nutrient-rich bean-based dishes like lentil soup, bean burritos, or rice and beans.
- Fill up on vegetables and fruit: Fruits and vegetables contain oodles of fiber, plus a variety of must-have vitamins and minerals. If possible, eat the skins of your fruits and veggies (they contain a lot of insoluble fiber), and always eat fiber-filled whole fruits instead of drinking fiber-less fruit juices.
So you're ready to dive right in and start your new fiber-rich diet, right? Well, take it easy or you'll pay a not-so-pleasant price. Adding a lot of fiber to your diet too quickly can cause intestinal gas, abdominal bloating, and cramping. You should increase roughage gradually over a period of a few weeks. And to avoid unnecessary bathroom "hang-ups" (that is, constipation), remember to drink plenty of water, which helps fiber pass smoothly through the digestive system.
Another fiber no-no is downing a big bowl of fiber flakes right before you do an endurance athletic event. In fact, too much fiber in a pre-event meal can lead to gassy cramps, bloating, heartburn, nausea, and a feeling of heaviness. Yikes. Not exactly what you want on race or game day.
About H.K. Jones: H. K. Jones is a registered dietitian, freelance writer, and nutrition professional based in Washington, D.C.