A sober reflection on the fiber craze: The current state of fortified fiber foods and misconceptions about energy.

If you eat few foods high in dietary fiber, your overall fiber intake will be limited. There has been great success in making weight-loss foods or constipation-preventing health foods with insoluble dietary fiber, and in making beverages with soluble dietary fiber. Foods with added dietary fiber are currently booming. In April 1989, the Tokyo Metropolitan Consumer Center in Minato Ward, Tokyo, published a survey report on the current status of foods with added dietary fiber. This survey investigated 39 types of food in the Tokyo area, including health foods, pastries, processed grains, and beverages with added dietary fiber.

For comparison, 12 similar food products without added dietary fiber were also investigated. Dietary fiber sources are diverse. Pastries and processed grain products often contain added corn fiber, wheat bran, and konjac glucomannan, while beverages often contain added glucan. According to the survey, pastries and processed grain products have an average dietary fiber content of 18.1%, approximately 3.5 times that of the same food products without added dietary fiber. In the beverage category, those without added dietary fiber contain an average of 0.6 grams of dietary fiber per 100 grams, while the same beverages with added dietary fiber contain 5.6 grams. From a dietary fiber intake perspective, it can be said that even 100% pure fruit juice is meaningless.

Among health foods labeled as having added dietary fiber, some even contain as much as 60% fiber. Overall, all foods labeled as having added dietary fiber have a significantly higher fiber content than their regular counterparts. Based on daily food intake, the majority (about three-quarters) of the dietary fiber intake from these fortified foods is less than 5 grams. Foods labeled as having added dietary fiber generally contain more fiber than their regular counterparts, typically more than three times the amount found in pastries and processed grains.

On average, it costs 22 yen (for beverages), 25 yen (for processed grains), and 68 yen (for health foods) to obtain 1 gram of dietary fiber. Health foods are quite expensive. Furthermore, from a calorie perspective, foods like cookies, even with added dietary fiber, are mostly not much different from their un-added counterparts; therefore, one cannot expect these foods to aid in weight loss. Adequate intake of dietary fiber is beneficial for maintaining health and preventing disease.