The concept of healthy ageing today is linked to the efforts of maintaining physical and mental independence, and to prevent the decline of physiological functions that are mandatory to guarantee a good quality of life. Yet, an individual’s ageing trajectory and underlying mechanisms are multifaceted and still far from understood. Hence, there is an urgent need for the further development of ageing phenotypes that can be utilized in the identification of biomarkers to characterize and predict biological age, taking into account the multiple dimensions of ageing. New technologies, often termed ‘systems biology’ approaches, are being increasingly applied to research focused on ageing populations. These technologies should enable investigators, and eventually clinicians, to (a) understand ageing metabolism in a more detailed and specific way; (b) enable the phenotypic characterization of many age-related disorders including chronic disease states; and (c) stratify older adults and the multiple comorbid conditions that may impact them.