(1) Data are presented on the change in body weight and food intake of young mature rats during the first and second trials on diets deficient in minerals and vitamins ; minerals, vitamins and bulk; and proteins. Data are also given on the loss in-body weight of rats during first and second fasts.
(2) The results show that, under the experimental conditions, rats ,which have lost weight as the result of a defective diet, and have then been restored to normal weight by stock ration did not show, as was found by French and Bloomfield, a more rapid weight loss, if now placed for a second time on the same defective diet. As a matter of fact in the majority of cases the animals lost slightly less weight during the second than during the first trial on defective diet. This was true no matter whether the rats had free access to their own excreta or not.
(3) Similarly, the food intake of the rats did not differ
appreciably during successive periods on the same defective diet.