Why was this study done?

Determining the optimal amount of fiber in the diet is a major health concern. This study was designed to investigate two different levels of fiber intake (2 grams, 11 grams) on fecal transit time (the time it takes food to move from mouth to anus).

What did the study find?

The study found that consuming 11 grams of insoluble fiber was enough to reduce transit time in most, but not all, participants in the study.

Correlation of Gastrointestinal Transit Time to Fecal Weight in Adult Humans at Two Levels of Fiber Intake
Authors: Spiller GA, et al. Nutr Rep Int, 1982. 25(1):23-30.
PDF Manuscript: Nutr Rep Int, 1982.