To cope with a projected global population increase from 7.2 bn to 9.6 bn by 2050, many more cities must be built. Although there are great benefits to modern urban living, there also great costs, such as the seemingly unstoppable rise in Type 2 diabetes, obesity, coronary issues and various cancers. The new towns should be designed to contain or constrain the epidemic of those ‘Western Lifestyle Diseases’ that currently plagues today’s cities. But how might this be achieved? It is suggested here that a greater understanding of human evolution combined with the potency of the ‘Palaeolithic genome’ holds the key to our future urban wellbeing. Consequently, a new paradigm is suggested that underpins positive forward thinking on townplanning and city lifestyles to create healthier urban environments. This builds directly on the ‘Evolutionary Determinants of Health’ programme initiated at University College London (UCL). A four-stage model is proposed that integrates and develops both evolutionary-concordant personal and institutional health behaviours with appropriately reconfigured town-planning and building regulations. When integrated, these strands could deliver a healthier urban culture within greened, active townscapes by proactively constraining or eliminating some of the key underlying causes of the so-called ‘Western Lifestyle Diseases’.