Worldwide countries are undergoing the ‘nutrition transition’ – a shift towards diets high in saturated fat, sugar and cheap processed energy-dense foods, with a corresponding increase in rates of obesity. The rich tend to move through the transition ahead of the poor, and with this the burden of obesity tends to shift from the rich to the poor as countries develop, in a process that has been called the ‘obesity transition’. This dissertation explores several aspects of the social gradient in body weight in South Africa using the nationally representative National Income Dynamics Study (NIDS) data, proposing that changes across and between generations and over the life course may be one of the drivers of the shift from one stage of the obesity transition to the next.