The mean daily intake of dietary fiber, sugar, starch, fat, protein, and total energy was determined in 35 patients with Crohn's disease and 70 normal controls by obtaining individual dietary histories. For each patient with Crohn's disease there two controls, matched for age, sex, and socioeconomic background. In the patients with Crohn's disease the mean dietary fiber intake was established as 26.6 +/- 1.4 g/day, compared to 22.3 +/- 0.9 g/day in the controls, and was thus significantly higher (P less than 0.05). When compared with the controls, the patients with Crohn's disease also exhibited a significantly higher consumption of sugar 156 +/- 14 versus 91 +/- 5 g/day (P less than 0.001), starch (211 +/- 10 versus 170 +/- 9 g/day (P less than 0.01)), and total energy (14.4 +/- 0.7 versus 12.3 +/- 0.5 MJ/ day (P less than 0.01)).