Integral characteristics of animal development (weight increase, maturing of biological systems) used to date are not adequate to the requirements of detailed biological evaluation of dietary fats. The linoleic acid content in the dietary fat and the eicosatrienoic acid - eicosatetraenoic acid ratio (20:3/20:4 = HOLMAN coefficient) in the organism alone are also inadequate criteria. For this reason, the author attempted to establish metabolism-relevant law-like relationships between the fatty acid pattern of dietary fats and tissue lipids.