British researchers working in Africa around in the 1960s noted that Africans had a much lower incidence of certain diseases, heart disease and diabetes in particular, compared to folks in Western cultures.
They figured the Africans' high-fiber diet had something to do with it, as most native Africans eat large quantities of unprocessed plant foods and very little fat or animal protein. They were right.
Since then, studies have borne that out, and scientists can track the relationship between higher fiber intake and reduced incidence of the same diseases in the U.S.
An ally to dieters
Strictly speaking, fiber really isn't much of a nutrient.
Dietary fibers are strings of sugar molecules, but the links between the molecules can't be broken down by our digestive enzymes, so these sugars pass through our bodies without being metabolized.
It provides bulk, but few or no calories. Because of this, fiber can be a great friend to people trying to lose weight or make the change to healthier eating habits. A study by Tufts University showed that when people consciously chose to consume more fiber, they reduced their overall caloric intake by about 18 percent.
The Tufts researchers attributed that to specific characteristics of high-fiber foods. High-fiber foods like vegetables and whole grains are generally lower calorie.
They also take more time to chew. And high-fiber foods stay in the stomach longer, keeping the feeling of fullness around, delaying the return of hunger.
Not just muffins, cereal
So what are your dietary fiber options? There are a lot of choices besides the usual bran muffin and those breakfast cereals hawked by the nutrition nerds. Dietary fiber comes in all sorts of fruits, vegetables and grains, and it comes in two types -- soluble and insoluble fiber.
- Insoluble fiber is the parts of plant matter that our digestive system can't really break down, so they pass right through. Insoluble fiber is abundant in unrefined cereals, whole-grain flours, fruits and vegetables.
- Soluble fiber dissolves in water, forming a thick, jelly-like substance. Soluble fiber lasts longer in the stomach than insoluble fiber, so it helps to keep your hunger at bay longer. Soluble fiber also changes very little as it passes through the body, acting mainly as a sponge and absorbing many times its weight in water.
Among the vegetables containing soluble fiber are beets, okra, carrots and dried beans. Oatmeal and legumes are other good sources. Vegetables containing insoluble fiber include cauliflower, onions, broccoli, mushrooms, spinach, potatoes, carrots and beans.
Caroline J. Cederquist is a board-certified family physician and bariatric physician. Get more information about Cederquist and her weight management plan by visiting www.DietToYourDoor.com.