Genetic information of DNA polymorphism, the functional genomic profile and the different response of an animal to a biologically active nutrient are used to identify the biologically active nutrient composition of the diet for an animal. The response to a nutrient exposure is dynamic since it depends upon the polymorphism of nutritionally inducible genes (as SNPs) that can lead to a different effect of the same nutrient in animals having different genotypes. The assessment of the biologically active nutrient composition of the diet arises from using reference data relating to normal healthy animals with different genotypes, target data relating to unhealthy animals with different genotypes, and nutritional data relating to a different effect of biologically active nutritional compounds in animals with different genotypes. Analysis is affected by relating gene, protein or metabolite expression.