Why was this study done?

Constipation is a condition that many people suffer from. This study was designed to investigate the role of hard wheat fiber on transit time (time it takes food to travel from mouth to anus) and increasing fiber’s effects on fecal weight, mineral, and steroid excretion. The study used three different amounts of fiber (5.7, 15.1, and 28.5 grams a day).

What did the study find?

All amounts of fiber increased fecal weight and reduced transit time. Mineral loss was noted at the highest level (28.5 grams) for calcium, but not for copper, zinc, iron, or magnesium. Steroid excretion was unaffected by any level of fiber supplementation.

Effect of increasing levels of hard wheat fiber on fecal weight, minerals and steroids and gastrointestinal transit time in healthy young women
Spiller GA, Story JA, Wong LG, Nunes JD, et al. J Nutr. 1986 May;116(5):778-85.
PubMed Citation PMID: 3009750.
PDF Manuscript: J Nutrition, 1986.

Earlier Abstract:

Spiller GA, et al. Effect of Four Levels of Hard Wheat Bran on Fecal Composition and Transit Time in Healthy Young Women. Fed Proc, 1984. 43(392).PDF Abstract: Fed Proc, 1984.