From the time of birth and throughout the lifecycle, the human organism depends on food and nutrients to sustain its growth, development and functionality. With increasing knowledge of biological processes within the human body, the term ‘you are what you eat’, takes on more and more meaning. One of the new levels of understanding relates to the interaction of food components with genes to set off cascades of events that affect health and disease (1). This new understanding provides a detailed view of the dynamic relationship between genes and the environment, represented through food. Our health, our lifespan, can be seen as a product of this continuous interaction, following a process of stimulation, utilization and response. Over time, these events take their toll and this could be viewed as ‘aging’. The challenge for nutrition is how to actively engage with this process, anticipate the downturns and use the available knowledge to slow the process, maintain functionality and assure quality of life for the years that remain. This review considers the significance of nutrition in two main areas that may be associated with aging: preventable or lifestyle related diseases such as obesity, diabetes, and cardiovascular disease, and the maintenance of functionality such as eyesight, cognition and physical activity.