title: Fecal characteristics in healthy young adults consuming defined liquid diets or a free-choice diet.
abstract: Fat and nitrogen absorption and fecal characteristics were studied in 10 healthy, young adults who ingested a free-choice diet for 12 days and then isocaloric amounts of one of two nutritionally complete liquid defined formula diets during a succeeding 12-day period. Apparent fat absorption was 98 to 99% of intake with both defined formula diets and 95% of intake on the free-choice diet. Nitrogen digestibility was determined during the liquid diet period, and averaged 95 to 98% of intake. There were no statistically significant differences between the liquid diets and the free-choice diets with respect to fecal wet or dry weight, transit time, or stool frequency. Individual stool weights averaged 83 to 96 g on the free-choice or liquid formula diets and were comparable to other values reported in the literature. These results support the theory that a critical volume of feces must accumulate in the colon before defecation occurs, regardless of diet composition.
mesh_terms: D000042:Absorption; D000328:Adult; D003672:Defecation; D004032:Diet; D004040:Dietary Carbohydrates / Q000032:analysis; D004041:Dietary Fats / Q000378:metabolism*; D004044:Dietary Proteins / Q000032:analysis; D004063:Digestion; D002149:Energy Intake; D005243:Feces / Q000032:analysis; D005260:Female; D005504:Food Analysis; D005526:Food, Formulated / Q000032:analysis; D005769:Gastrointestinal Motility; D006801:Humans; D008297:Male; D009584:Nitrogen / Q000378:metabolism*
chemical_list: D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins; D009584:Nitrogen