Both genetics and nutrition have a significant impact on human health and the course of disease. Certain people and populations may have a higher risk of disease as a result of the interplay of genetic and nutritional factors. Diet-gene association studies have recently provided evidence to support the results of gene-specific dietary intervention trials. A new approach to nutrition is provided by nutrigenomics, which has made it possible to clarify how food affects the genetic code, how the organism reacts to these disruptions and how these affect the phenotypic. Numerous factors, including age, sex, physical activity, smoking and genetics, might affect how a person reacts to their food. Additionally, individualised nutritional counselling based on nutrigenomics emerged as a result of advancements in nutrition sciences, marketing and communication. Finding people who benefit from a certain nutritional intervention and finding alternatives for those who do not are the objectives of personalised nutrition. The way doctors and other professionals assess and treat various diseases has improved since the advent of nutrigenomics. The literature on how diet affects whole-body metabolism-that is, genes, proteins and metabolites-as well as how genotype affects nutritionally associated diseases, has been compiled in this study.