Getting enough fiber in your diet is difficult, especially when you are on a low-carbohydrate diet. But if you eat enough of the right foods that are high in fiber, it is possible.
My previous blog entry on "Fiber and Diabetes" raised many questions, both in the comments and email to me, about what to eat. That blog entry focused on the general sources of fiber. This one focuses on particular foods that are high in fiber.
Most of us think that we are getting enough fiber. We aren't.
When researchers asked people if the amount of fiber they consume is "about right," 73 percent of those who consumed less than 20 grams per day agreed. This comes from the "Third National Health and Nutrition Examination Survey" cited in the American Dietetic Association's position statement on "The Health Implications of Dietary Fiber".
The American Dietetic Association goes on to say that healthy adults need 20 to 35 grams of fiber per day. We don't meet that need "because intakes of good sources of dietary fiber, fruits, vegetables, whole and high-fiber grain products and legumes are low."
More specifically the Food and Nutrition Board recently set the adequate intake level of total fiber at 25 grams per day for young women and 38 grams per day for young men. Young means less than 51 years old.
Old women need only 21 grams per day and old men need only 30. That's because old folks don't eat as much, they say.
This Food and Nutrition Board is semi-official. It's a unit of the Institute of Medicine, which in turn is a part of the National Academy of Sciences, a private, nonprofit corporation created by an Act of Congress. It acts as an adviser to the federal government on issues of medical care, research, and education.
To find the specific foods that will help us to make up this gap I turned to my "Fiber" file, where I have been saving this sort of resource for years. Two of the best sources are not free online. Plant Fiber in Foods by James W. Anderson is a 1990 booklet of the HCF Nutrition Research Foundation, P.O. Box 22124, Lexington, KY 40522. Only the abstract of "Content and composition of dietary fiber in 117 frequently consumed foods" by Judith A. Marlett in the February 1992 issue of the Journal of the American Dietetic Association is free online.
But we do have two excellent online resources about fiber in specific foods. Dr. Anderson's "Dietary fiber content of selected foods" came out in an 1988 issue of the American Journal of Clinical Nutrition. Less technical but perhaps more useful for most of us is Northwestern University's "Nutrition Fact Sheet: Dietary Fiber".
Starting with the Northwestern fact sheet you can get 5 to 7 grams of fiber from a cooked half cup of most legumes or beans. Then, barley is the cereal grain with the most fiber, about 4 grams in a half cup. That's fortunate, because barley has the lowest glycemic index of any grain.
Among fruits, a medium apple will give you about 6 grams more of fiber. An orange or a pear have almost as much. Three small figs - when you can get them - will give you 5 grams. A half cup of raspberries will give you 4 grams.
Some vegetables too are high in fiber. The highest is a medium artichoke with 6.5 grams. Other excellent vegetable sources are jicama, peas and sweet potatoes.
One correspondent asked about one of my favorite vegetables, okra. Northwestern doesn't mention it, but Dr. Anderson's booklet says that it has about 4 grams per half cup.
A half cup of uncooked oatmeal will provide 4 grams of fiber, according to Dr. Anderson's booklet. Whole Control barley cereal has about 50 percent more fiber than oatmeal.
Others asked about fenugreek, flax seeds and chia seeds. They are all excellent foods and good sources of fiber, but few of us will eat enough of them to get a substantial additional fiber hit. The USDA National Nutrient Database shows major ingredients, including fiber, of these and about 7,000 other foods.
Someone else asked about psyllium. This is probably the most common fiber supplement, and the one that I have taken ever since I reviewed Worst Pills, Best Pills.
Many experts argue against fiber supplements for several reasons, but I don't know how to get enough fiber in my diet without psyllium. I take three capsules with each meal and assumed that I was adding a lot of fiber. But they add up to only 3.3 grams of fiber per day. The psyllium supplement has become an even more important part of my diet since I started Byetta and now eat much less.
If I were truly following a low-carb diet, such as Dr. Richard K. Bernstein recommends, I don't see how I could get anywhere as much fiber as the experts say we should get. But, like with everything else, Dr. Bernstein differs here too from the medical establishment.
"Fiber, like carbohydrate, is not essential for a healthy life. Just look at the Eskimos" he writes in his most recent book, The Diabetes Diet. If you do want to increase the fiber content of your meals, he suggests "salads, bran crackers, and soybean products."
The three low-carb bran crackers that he recommended in his previous book, Dr. Bernstein's Diabetes Solution, are G/G Scandinavian Bran Crispbread and Bran-A Crisp — both from Norway and not easy to find — and Wasa Fiber Rye, which is readily available in supermarkets. "Many of my patients feel that this (the Wasa Fiber Rye) is the tastiest of these three products." I agree. The other two taste to me a lot like cardboard.
There isn't any fiber in meat, poultry, seafood, dairy products, eggs or fats. So unless you are a vegan (and I'm not), it seems to me that you have a choice. You either eat too much food or too little fiber. Most of us probably do both.