The purpose of this research is to study the infl uence of food ration options with low and high protein contents on the biochemical indices of senile rats. Thus, low levels of ALT were detected in group 2, which determines liver disease.  Glucose (GLUHK) levels, decreased in group 2, and increased in group 3. We observed a signifi cant increase in cholesterol levels in group 3, while in  group 2 the levels were lower than those of the control group.  Low levels of urea (UREA) in our experiments make us suspect kidney malfunction. In the group with a protein-rich diet, creatinine levels increase by 1 U / L, as compared to the control group; in group 3, however, creatinine levels increase signifi cantly, by 4.87 U / L as compared to the control group, which is probably due to renal insuffi ciency in the rats in group 3. Decreased levels of albumin, total proteins, of bilirubin and increased lactatedehydrogenase levels attest to the fact that we have observed liver failure.