Experiments were done to determine whether undernutrition with consequent loss of weight or failure to gain weight inhibited the development or promoted the regression of the aortic lesions of experimental cholesterol atherosclerosis in the rabbit. The experiments were conducted in such a way as to determine whether undernourished and adequately nourished rabbits fed the same daily doses of cholesterol would manifest different degrees of atherosclerosis at the end of an experiment.
Different experiments tested the effect of undernutrition in young, growing animals that failed to gain weight normally (Experiments 1 and 2); in young rabbits subjected to marked undernutrition both before and during cholesterol feeding (Experiment 3); in fully grown, mature rabbits that lost weight during undernutrition (Experiment 4); and in rabbits that had completed a period of cholesterol feeding before caloric restriction was begun (Experiment 5).
In every experiment it was observed that, if two groups of rabbits were fed cholesterol, one group being subjected to caloric restriction while the other received an adequate diet, no difference in aortic atherosclerosis was observed between the two groups at the termination of the experiment. Furthermore, no obvious effect of undernutrition on the regression of atherosclerotic lesions was observed in the rabbit.
At the same time, undernutrition was found to promote hypercholesterolemia in the rabbit fed cholesterol. The possible significance of this result was discussed.