Lifepath defines healthy ageing as the optimal state of performance and wellbeing capable for any particular phase of the life-course that can be expected in a society, across all social and cultural groups of a population. Healthy ageing is an achievable goal in society as it is already experienced by individuals in the highest socioeconomic groups. This postulate is based on three main hypotheses:

1. healthy ageing begins at conception, if not before;
2. ageing involves a progressive differentiation across social groups;
3. biological changes underpin the effect of complex environmental, behavioural and social patterns and can be traced with omic technologies.

Environmental and social circumstances influence healthy aging by determining the maximum attained health in early-life. This stage is defined as the build-up phase. In later life (defined as the decline phase), they influence ageing processes through earlier and/or steeper declines in capacity, function, wellbeing, and increased pathology and mortality. The gap between social groups in terms of mortality, functional performances and cognitive capacity accumulates over these two phases, resulting in widening inequalities with ageing.
Ageing processes are thus set up from the beginning of life, if not from one generation to another. This takes the notion of ageing away from an individual focus, thus putting the responsibility to facilitate better environments for populations of all ages on society and social structures.