Consumers are increasingly demanding transparency in food labelling as they want more and better information about what they are eating and where their food comes from. Several food indexes have been developed in the last decades to promote healthy eating with the aim to reduce certain diseases such as obesity, cancer, diabetes. The Mediterranean diet is known to be one of the healthiest dietary patterns and it is associated with a lower incidence of mortality from all-causes, and it is also related to lower incidence of cardiovascular diseases, type 2 diabetes, certain types of cancer, and neurodegenerative diseases, but a comprehensive index that quantifies the Mediteraneaness of foods is still missing. The real European challenge is to identify a uniform labelling system for the whole of Europe which promotes a healthy lifestyle. This article describes the development of the Mediterranean Index (MI), which aims to accurately measure the degree of food Mediterraneaness. The MI simultaneously integrates nutritional and sustainability characteristics of foods. The MI may provide an objective basis for the use of the “Mediterraneaness” label on food products, which can ultimately to promote adherence to the Mediterranean diet encouraging producers to make healthier and more sustainable food products. Growing consumer concern to-ward health foods for better health can be a factor useful to promote the applicability of the precision nutrition principles by means conscious choice.