Abstract:Integrating individual and environmental factors to achieve risk prediction and prevention of diseases at the individual level is the core of precision medicine and the direction of precision nutrition development. However, due to the lack of theoretical basis and research methods, the development of precision nutrition or personalized nutrition is relatively slow. N-of-1 trial is a randomized, double-blind, multiple-crossover trial that uses a single individual as a control to evaluate the efficacy of one intervention compared with another intervention, and it has a first-level evidence level. N-of-1 trials may play a key role in distinguishing subjects individual responses to different dietary structures, nutrients or nutrient supplements, and select better dietary nutrition strategies for individuals, which is extremely important in precision nutrition research,and has methodological value and application potential.