James was born in Bath and educated in King's College London (BSc 2006, PhD 2010 with Simon Hughes) where he examined the contribution of stem cells to muscle and pigmentation patterning. He pursued postdoctoral studies with John Rawls at Duke University, USA on adipogenesis before returning to the Centre for Cardiovascular Science at the University of Edinburgh as an EPICT Fellow. His lab studies how genetic and environmental factors regulate adiposity traits such as early-onset obesity, body fat distribution and adipose tissue morphology at Edinburgh, where he is now a Senior Lecturer.