The nature of food is that its primary purpose is to provide macro and micronutrients. These impact upon nutrition and primary metabolic pathways. Nutrition can be considered at various levels of granularity and can be reflective of population and individual health. This raises the question of how to measure health—apart from nutrient deficiency—and what is the role of non-nutritive food components? Nutrient deficiency has a number of clinical outcomes (depending on severity) and these can be measured. It is, however, more difficult to assess optimal inputs of nutrients and, in particular, non-nutrients. Clinical endpoints are difficult to define and changes in them challenging to ascribe to particular food components.