Influence of the Protein Level of the Diet on the Longevity of Cockroaches12

Diet has a great influence on the well being and longevity of animals. By restricting caloric intake McCay and co-workers (1935) brought about retardation of growth in young rats that resulted in increase in the total life span of these experimental animals. In a later paper, reporting the results of their study of the nutritional requirements during the later half of life, McCay and co-workers (1941), stated: “The optimal conditions for a long life (of rats) proved to be thin bodies, exercise and a low protein diet with the protein supplied by liver.” Slonaker's (1935) experiments also indicated that the life span of both virgin and bachelor rats was shortest in the group which were fed higher (26%) protein diet. Unfortunately, he used a rather small number of animals in his assay experiments.