The development of individualized nutrition systems is relevant to the personalized medicine of the future. The paper presents the fundamental principles of sanogenic nutrition according to the type of constitution (the normosthenic type of constitution), which was used as a criterion for individualization. In order to perform the tasks of the research stage, 4 variants of rations with different calorific value for the normosthenic type of constitution were elaborated. In order to interpret the biological value of the rations used more widely, the entire spectrum of amino acids has been studied. For the assessment of general physiological status, free amino acid pool in rat blood serum and erythrocytes was evaluated. In normosthenic rats, maintained with rations with 16-20% protein, the antioxidant potential of the body is within stable limits, which reflects the limits of the compensatory possibilities of the organism of normosthenic rats. The optimal coefficient of distribution of amino nitrogen between erythrocytes and serum in the blood is also 1.8 and is closer to the optimal one.