Because the variation in fiber intake within the highest quintile was much greater than that within the other quintiles (Table 1), we also analyzed total fiber as a continuous variable. In multivariate analyses, each increment of 10 g per day in total fiber intake corresponded to a relative risk of colorectal cancer of 0.99 (95 percent confidence interval, 0.83 to 1.17). To evaluate extreme levels of dietary fiber consumption, we repeated our analysis after categorizing fiber intake according to energy-adjusted deciles. As compared with women in the lowest decile (median intake, 8.5 g per day), women in the highest decile (median intake, 28.5 g per day) had a relative risk of colorectal cancer of 1.01 (95 percent confidence interval, 0.71 to 1.