It is predicted that in the near future there will be a trend for the development of genetically-modified foods with enriched nutrients, better functionality, and medicinal ingredients, which will be of benefit to the consumer. One line of development will be aimed at the prevention of life-style-related diseases, for example high-oleic soybean oil and oil seeds enriched with n-3-type fatty acids. Another aim will be to overcome malnutrition in the developing countries, for instance by producing rice high in β-carotene, iron and protein. On the other hand, since genetically-modified foods are a matter of some concern among consumers, it will be necessary to establish methods for safety assessment. However, it is generally impossible to conduct safety assessments of genetically-modified foods in human subjects. Accordingly, we propose an evaluation method, in addition to the regular assessment supervised by the Ministry of Health and Welfare, which replaces common foods with genetically-modified foods and then simulates nutrient intake from genetically-modified foods according to the National Nutrition Survey in Japan and Standard Table of Food Composition in Japan.