If your diet is composed of high-fat, highly processed foods, sprinkling a little bran on your cereal is not the ideal way to get an adequate amount of fiber. Neither will going to the other extreme help you: Adding 40 to 60 grams of supplemental fiber in powder or pill form would be excessive and could possibly lead to nutrient-absorption problems. In fact, the American Institute for Cancer Research recommends getting fiber from foods rather than from fiber supplements.10
While today's new focus on fiber is encouraging, some health-professionals and best-selling diet books have unfortunately chosen to recommend fiber supplements instead of suggesting changes in basic eating habits. This practice may be self-defeating, because it's rather like choosing to take an antidote instead of eliminating the poison itself. Meals that are high in fat and cholesterol and low in unrefined carbohydrates put us at risk for chronic diseases and obesity - and fiber supplements are not the magical correction for these imbalances. It's true that adding fiber will help lower two risk factors associated with high-fat diets - high cholesterol and colon cancer - but fiber supplements will not address the other health risks associated with a high-fat diet.
Fiber supplements are also a poor substitute for real food - unprocessed, fiber-rich carbohydrates with all their nutritional advantages. What's more, they are expensive and can easily lull people into complacency ("My diet is healthy - I add fiber to it every day, don't I?"). With growing numbers of people becoming more conscious of the benefits of fiber, health authorities would be better advised to help them improve their daily diets instead of offering them yet another drugstore prescription.