Fiber, sometimes called roughage, is an important dietary component that is often under-consumed in our modern “fast food” lifestyles. In ancient times, dietary fiber was commonly ingested as primitive man foraged for wild, fiber-rich vegetables and fruits. Today, we forage for food at Mickey D’s, Jack-in-the-Box, and the frozen food section of the supermarket. Most of us ingest less than 20% of the amount of fiber that our early ancestors ate. Even as recently as the beginning of this century, fiber-rich foods were commonplace in our eat-at-home meals. Today, all too frequently, our fiber consists of a limp, mayonnaise-slathered wisp of lettuce laying on top of a double cheeseburger.
So what do you need to know about fiber? And how should you go about enriching your diet with this health-promoting foodstuff?
What is fiber?
Fiber is a term that encompasses a variety of substances found in plant foods. These substances, such as cellulose, hemicellulose, pectin, lignin. and so forth are not readily digestible by humans. So they stay in the intestines where they exert a variety of beneficial effects.
There are two main categories of fiber:
- Insoluble fibers, such as cellulose or hemicellulose, are found in wheat bran, whole-wheat flour, nuts, and many vegetables. These fibers do not dissolve in water. They are also not broken down by digestives enzymes, so they stay in the intestines where they absorb water and help speed up the movement of material through your gut. A major benefit of insoluble fibers (when they are taken with an adequate amount of fluid) is large, soft, easy-to-pass stools. It is controversial whether or not this conveys protection against colon cancer. A recent study, published in the journal Diabetes Care also documented significant improvement in insulin sensitivity in overweight and obese women eating an insoluble fiber-enriched bread compared to women who ate regular white bread.
- Soluble fibers (gums and pectins) do dissolve in water to form a gel-like material. Soluble fibers are found in oats, peas, beans, apples (particularly apple skin), citrus fruits, carrots, barley, and psyllium (e.g., Metamucil). Soluble fibers tend to retard the absorption of foods, thereby, moderating how high blood glucose will rise after a meal. Diets rich in soluble fibers lower blood cholesterol, help improve blood sugar levels in diabetics, and may reduce the risk of developing type 2 diabetes.
Other benefits of fiber include help with weight loss. There are a number of reasons for this. It takes longer to chew high-fiber foods. Eating more slowly allows the body time to develop its satiety response, signaling that you are full and should not eat anymore. Many high-fiber foodstuffs also fill you up with less calories than many refined, sugar- and fat-rich foods. Be careful though, many foods advertised as high fiber may end up being sweetened and full of fat to increase their palatability.
How much fiber should I eat each day?
The National Academy of Sciences’ Institute of Medicine recommends the following:
- 38 grams/day for men age 50 and younger; 30 grams for age 51 and older
- 25 grams/day for women age 50 and younger and 21 grams for age 51 and older
How can I increase fiber in my diet?
There are a few simple things that you can do that will increase fiber in the diet—tell me you haven’t heard this before”
- Buy whole-grain products instead of products made from highly refined grains and flours that have had the fiber removed. Some of these foods are flat out delicious, like bulgher, brown rice, kasha, and barley. A caveat, however, if you are baking with whole wheat flour, you may need to increase the amount of yeast you use to get the bread to rise (does anyone really make bread anymore??)
- Do not peel your fruits and vegetables. Eat that apple with its skin. Don’t peel carrots or beets or other root plants before you cook them. Once you get used to it, you will enjoy the look and taste of these “whole foods”.
- Consumption of fruit juices is quite high in some areas of the country due to the proliferation of juice stores, like Jamba Juice and others. Be careful. Many of these drinks are very high in calories (Jamba Juice drinks can range from a low of 160 calories to a whopping 960 calories for the “power” version of “Peenya Kowlada.”) The also may not be a fiber-rich as eating the whole fruit.
- Eat your veggies raw whenever possible. Cooking vegetables, especially cooking until soggy, breaks down the fiber, can leach out nutrients, and, by the way, makes them taste yukkie. Try lightly steaming for the best results. Microwave ready vegetable packs are increasingly appearing in many grocery stores. If you have a farmer’s market in your area, make it a point to buy your produce there. Buying locally helps promote an independent, sustainable fresh food marketplace.
- Start the day with a high fiber cereal, such as Kellogg’s Bran Buds or General Mills Fiber One. CNN Food Central has a list of high-fiber cereals that you may find helpful.
- Don’t get fooled by the advertising on the front of the cereal packages. The difference in fiber content can be substantial. Kellogg’s Bran Buds, for example, has 39 grams of dietary fiber (9 soluble and 30 insoluble) for each cup eaten. Old Fashioned Oats (Safeway brand) has 8 grams of fiber (4 soluble and 4 insoluble) per cup of cereal, and Cheerios, despite its banner proclaiming “the Soluble Fiber in Cheerios Can Reduce Your Cholesterol” has only 3 grams of dietary fiber/cup (1 gram from soluble fiber and the rest insoluble fiber). On the other hand, a cup of Cheerios has 110 calories compared to Bran Buds’ 210 calories. Bran Buds also uses high fructose corn syrup as a sweetener.
- LEARN TO READ FOOD LABELS. Remember to compare serving sizes when you are trying to figure out which cereal is best for you.
- Add crushed bran cereal or unprocessed wheat bran to foods that you cook or just sprinkle it on top of salads, casseroles or cooked vegetables. You can buy wheat germ at most supermarkets or unprocessed wheat bran in bulk at Whole Foods or other health foods stores.
- Eat your legumes…peas and beans are an excellent source of fiber.
- Try to increase the fiber in your diet via your diet and not solely by food supplements. Fiber-rich foods, particularly fruits and vegetables, are also rich in other nutrients, like vitamins. Further, many nutritionists and endocrinologists recommend getting healthy by a healthy diet as opposed to trying to offset an unhealthy diet with supplements.
Are there any side effects of a high fiber diet?
Too much fiber can cause gas, bloating and cramping. It is probably best to increase the fiber in your diet over a period of a few weeks. Also, drink lots of water. Fiber absorbs water and makes the stool soft and bulky. Failure to drink enough water can cause constipation.
The bottom line
A high fiber diet has many health benefits, including improved blood glucose and cholesterol and, if eaten as a part of a calorically appropriate diet, fiber may help with weight loss.