Water-Food Interrelationships in Rats Fed Chemically Defined Liquid Diets.

Abstract

Summary A chemically defined liquid diet was found to be well suited for studying water:nutrient interrelationships. When supplied as the sole source of water and solid nutrients such a diet can satisfy the nutritive requirements of the growing rat. In this study rats fed diets containing 30% (w/v) or 40% (w/v) solids as the sole source of water and nutrients appeared healthy and grew well. Under the same conditions a 50% (w/v) diet proved hypertonic, promoted slower growth and produced highly concentrated, hypertonic urine. More diluted (10% and 20%) diets were also inadequate, but, in this case, the cause was probably poor diet utilization. When drinking water was provided with a diet containing 50% (w/v) solids, good growth was obtained and urinary specific gravity and osmolarity were reduced.