Abstract
Before 1995 biogerontology came down to description of specific age-associated diseases. The last twenty-five years biomedical gerontology has started to aim at explanation of underlying processes of senescence and at (genetic, dietary, and pharmacologic) interventions and technology to delay those processes. ‘Geroscientists’ such as Brian Kennedy and Felipe Sierra have been writing about the ‘Prospects for Life Span Extension’ and have argued that ‘it is critical to expand geroscience research directed at extending human healthspan’. They pay attention to social effects that might occur, but issues of social justice are mostly ignored. In this paper an ethical-philosophical argument is developed. It makes plausible that fighting obesity might be more efficacious in extending life span and health span and also more ethically just than developing sophisticated and expensive technology to delay processes of senescence. It is not a matter of one or the other, but priorities should be debated.