The Importance of the Time Element in Feeding of Growing Rats: Experiments With Delayed Supplementation of Protein

Abstract

Three types of diets adequate for growth of young rats were set up. Diet A was protein free; Diet B contained 50% washed casein and 50% fish proteins; Diet C contained 80% of Diet A and 20% of Diet B. Exptl. rats were fed Diet A from 4:00 P.M. until 7:30 A.M. the next day. The amt. of food consumed by each rat was detd. Between 11:00 A.M. 1:00 P.M. sufficient amts. of Diet B were fed to give 20% protein during the day. The next day controls were given an amt. of Diet C equal to the total of the diets consumed by their corresponding animals on the mixed diet. The controls were allowed 80% of their total ration from 4:00 P.M. to 7:30 A.M., and 20% from 11:00 A.M. to 1:00 P.M. The exptl. rats fed the separate diets failed to grow at a rate comparable to the controls. In 21 days the controls showed an avg. wt. gain of 95 g., while the exptl. animals showed a gain of only 62 g. Expts. with adults with protein depletion showed that the wt. increase during protein restoration was retarded if the protein and other foods were fed at separate times.