Effects of Experimental Diets and Simulated Space Conditions on the Nature of Human Waste
Abstract
The effects of three different types of experimental diets and three environmental conditions on the nature of human waste were evaluated in a series of experiments over a 2-year period to provide waste management criteria for space systems. These effects were assessed in 36 healthy subjects in terms of defecation rate, fecal mass, protein, fat, fiber, and physical characteristics, along with some urine properties and water consumption. Dehydrated foods, full pressure suits, strict confinement and heat stress (32 C) did not alter any of the waste properties. The liquid foods under examination caused a significant but not consistent increase in fecal mass. The greatest effect of diet was observed with compressed bite-sized food, resulting in a significant (P < 0.01) and persistent increase in fecal fat and mass as well as a change to a soft fecal consistency. This steatorrhea condition plus the high correlation of fat between experimental diet and feces emphasize the importance of selecting the proper quality of fat in the diet. Differences between and within subjects were observed. Time differences and interactions varied according to experimental design or condition; these differences plus some degree of carry-over in feces from one diet into another diet period stress the importance of having adequate adjustment periods before evaluation of diets. Other characteristics of the diet were evaluated also. Of all the experimental conditions studied, only heat stress caused a very significant change in water consumption.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1966
- Accession Number
- AD0659143
Entities
People
- A. R. Slonim
- T. H. Mohlman
Organizations
- Miami Valley Hospital