The revelation of the human genome has enabled scientists to assess the disposition and response of an organism to an environmental stimulus; transcriptomics, proteomics, and metabonomics can each generate such holistic views. Nutrigenomic techniques help researchers elucidate individual responses to nutritional interventions holistically and help with the design of personalized diets adapted to individual needs. Human genetics has revealed insights into health and disease susceptibility and can help differentiate responders from nonresponders in dietary interventions, but the predictive power of single-nucleotide polymorphisms in disease susceptibility genes has so far been limited in terms of helping to foresee a health trajectory. Epigenetics encompasses alterations of genetic material that do not affect the DNA nucleotide sequence; these include DNA methylation patterns, chromatin structure, histone codes, and non-coding small RNAs. DNA methylation is modified particularly around the time of birth; therefore, early-life nutrition may affect health outcomes later in life.