This paper seeks to bring concepts from economic geography and human geography into closer dialogue and apply them to the analysis of food systems. We analyze temporal and spatial patterns of diet transformation in Bangladesh using data from nationally representative household surveys. We conceptualize diet transformation as a ‘triangle’ comprised of three elements (food purchases, diet diversification, and processed food consumption), influenced by four conditioners (time, income, non-farm employment, and space). We find that: (1) Diets are converging over time and space. food purchases, non-staples, and processed foods occupy high shares of food consumption value, irrespective of urban or rural location. Controlling for income, rural landless households and households in urban areas have very similar diets. Households in ‘peripheral’ and ‘non-peripheral’ rural areas experience similar levels of diet transformation. (2) Food purchases and processed food consumption are conditioned mainly by non-farm employment (NFE). (3) Diet diversification is positively associated with income, but not with NFE or land ownership. We characterize the spatial convergence of diets as an outcome of ‘time-space compression’ (the accelerating volume and velocity of economic and social transactions resulting from advances in transport and communications technology), and the distinct form of peri-urbanization under conditions of extremely high population density found in Bangladesh.