Why You Need More Fiber
High-fiber foods boost health and help control your weight
By Elaine Magee, MPH, RD
Reviewed By Louise Chang, MD
Most of us haven't a clue how many grams of fiber we get from our diets in on a typical day. Yet for many Americans, this number should be doubled.
A recent American Dietetic Association position paper reported that most of us don't even come close to the recommended intake of 20 grams to 35 grams of fiber a day. Americans' mean fiber intake is about half that --14-15 grams a day.
That's not surprising when you consider that we get fiber from 'roughage' like fruits, vegetables, whole grains, nuts/seeds, and beans. The typical American isn't exactly loading his or her plate with these foods (you'd be hard-pressed to find a fruit, vegetable, whole grain, or bean in your average fast-food value meal).
Why Is Fiber so Good for Us?
Eating a higher-fiber diet has been shown to lower blood cholesterol levels, improve and prevent constipation, and slow digestion. And according to Barbara Rolls, PhD, author of The Volumetrics Eating Plan, fiber can help us eat less -- and lose weight.
"Simply doubling the amount of fiber you eat from the average of 15 grams per day to around 30 grams helps reduce calorie intake," Rolls explains. "Fiber has been shown to increase satiety, not only by lowering the energy density of foods (that is, how many calories they have per serving) but also by slowing the rate that foods pass through the digestive systems."
When you increase dietary fiber, do it gradually to avoid gastric distress, and to drink plenty of fluid (8 cups per day) to avoid constipation.
Joanne Slavin, PhD, an obesity researcher with the University of Minnesota, says dietary fiber not only makes us feel fuller, but reduces digestibility. Some studies have shown that large amounts of fiber in the diet can help regulate blood glucose and insulin. These may be reasons why people who eat higher-fiber diets tend to weigh less and are less prone to gain weight as they age.
"The best protection is at the highest fiber intakes -- at least 25 grams a day recommended for women," says Slavin.
The research findings on fiber's benefits keep pouring in. Some recent studies have shown that:
Fiber intake has also been linked to the metabolic syndrome, a cluster of risk factors that increase the chances of developing heart disease and diabetes:
The 2 Types of Fiber
Though both have health benefits, there's a difference between the insoluble, type of fiber found in whole grains, carrots, tomatoes, and lettuce, and the softer, water-soluble type found in oatmeal, pears, strawberries, and apples.