INTAKE RATIO OF WATER-INSOLUBLE DIETARY FIBER TO THE WATER-SOLUBLE ONE IN JAPANESE - AN ESTIMATION ON DIETARY RECORDS AND THE SECULAR CONSIDERATION ON THE NATIONAL NUTRITION SURVEY

Thirty-four foods were analyzed in order to determine the content of w ater-soluble dietary fiber (SDF) and insoluble dietary fiber (IDF). Us ing the results with the standard table for 227 foods, the intake rati o of IDF/SDF of an average Japanese was calculated for the period 1946 -1990. The ratio was 3.22 in 1990 as calculated on the food intakes sh own in the national nutrition survey, and the secular change was not d etected since 1946 when the ratio was 3.30. The ratio was also shown t o be well preserved between types of households including the age of t he head. Using dietary records of 60 healthy city workers (average 42. 8 years) for 4 weeks, however, the weekly average ratio for an individ ual was found to vary in the range of 2.25-5.13 although the total ave rage for 60 individuals was 3.33. Thus, the well preserved IDF/SDF int ake ratio for an average Japanese showed, on the contrary, a wide vari ation of food selection between each person.