[Trends of the dietary fiber intake among Chinese aged 18 - 45 in nine provinces (autonomous region) from 1989 to 2006].

Objective: To analyze the status and trend of dietary fiber intake and its food sources among Chinese residents aged 18 - 45 years old in 9 provinces (autonomous region), from 1989 to 2006.
Methods: Twenty-four-hour dietary recall data of three consecutive days from China Health and Nutrition Survey (1989, 1991, 1993, 1997, 2000, 2004 and 2006) were used. And the 18 - 45 years old subjects with complete information on dietary survey were included. The sample size of these 7 surveys were 5597, 5596, 5323, 5485, 5308, 4144 and 3889, respectively. The trends of dietary fiber intake and food sources by time and sex were studied.
Results: From 1989 to 2000, the total of daily dietary fiber intake of 18 - 45 years old healthy residents decreased from 15.1 g/d to 11.6 g/d, insoluble dietary fiber intake decreased from 22.6 g/d to 17.8 g/d. In villages, from 1989 to 2000, the insoluble dietary fiber intake decreased 5.1 g/d in males and 5.2 g/d in females(13.2, 11.8 g in 2000, respectively;18.3, 17.0 g in 1989, respectively). In 2006, the insoluble dietary intake was 12.6 g/d in males and 11.2 g/d in females in villages. In cities, from 1989 to 2006, the insoluble dietary fiber intake was 9.4 - 11.8 g/d in males and 8.3 - 10.8 g/d in females. The total dietary fiber intake was 15.7 - 17.6 g/d in males and 13.5 - 16.4 g/d in females. The difference of insoluble and total dietary fiber intake between city and village was decreasing. In 2006, 70.6% (8.4/11.9) insoluble dietary fiber came from vegetables ((4.1 ± 3.1) g/d), wheat flour and its products ((2.6 ± 3.6) g/d), rice and its products ((1.7 ± 1.3) g/d).
Conclusion: Dietary fiber intake among Chinese aged 18 - 45 in 9 provinces (autonomous region) decreased from 1989 to 2006. Vegetables, wheat flour, rice and their products were the major food sources of insoluble dietary fiber.