This paper explores the environmental impacts of dietary changes consistent with the nutrition transition common in countries going through economic development, inferred from commodity supply data from FAOSTAT. Supply data for 1961 and 2011 from three case study countries which have undergone significant economic transition in recent decades (Brazil, China and India) were compared on a per-capita basis to avoid confounding issues of population growth. Brazil showed marked increases in beef and poultry meat supply (kcal) while in China poultry and pig meat showed marked increases, particularly for pig meat. Per-capita supply of fruit in Brazil and vegetables in China were higher than in Europe by 2011. Supply of vegetable oil increased in all three countries and this was the majority commodity traded, hence much of its impact would have been felt in country of origin. The increase in beef production in Brazil, attributed to changing diet (2001–2011), had the greatest impact on increased water use, although the increase in supply of pig meat in China and cereals in China and India (attributable to changing diets) also made major contributions. The increase in cereal supply in China and India had a major impact on phosphorus and nitrogen cycles, with beef having a major impact on greenhouse gas emissions (GHGs). The increase in vegetable oils had a major impact through increasing land use. These findings highlight differential environmental impacts of the nutrition transition in different countries and emphasise the need to measure environmental impacts beyond those on GHGs.