Changes in the crude fiber content of the American diet.

The intake of crude fiber in the American diet was assessed for 7 time periods between 1909 and 1975 using food consumption and composition tables. Crude fiber intake dropped 28% from 6.8 g/day in 1909 to 4.9 g/day in 1957 to 1959 and has remained at that level until the present. The intake of fiber from vegetables has remained relatively constant from 1909 to 1975 while potatoes, fruit, cereals, dry peas, and dry bean consumption have declined. The trends shown for crude fiber consumption in the United States support the hypothesis that fiber intake has decreased coincidentally with increases in degenerative diseases.