Why do we talk about food system transformation?There is broad scientific consensus about the negative impacts that most food systems are having on climate change, biodiversity, healthy diets, and livelihoods for smallholder farmers and the urban poor (EAT Lancet 2019; CFS-HLPE 2020; GLOPAN 2020). Policymakers recognise this, and argue that the policies that fed the world in the twentieth century are no longer fit for purpose (this is reflected in statements and commitments from the UN Food Systems Summit (UNFSS), 1 Nutrition For Growth (N4G) 2 , and the Climate Change COP26 3 meetings in 2021). In other words, the call for food system transformation has never been stronger.The term 'food system transformation' refers to how to change food systems. It is important to note that transformation is a radical idea. It is not a tweak, but a complete rethink of the attributes of a food system, including its purpose, rules, and power structures. It is about reshaping the so-called 'normal'. Whether deliberately steered, or occurring autonomously, there will be will transformation winners and losers.Food system transformation includes rethinking the key outcomes of food systems. Until about 20 years ago, the main expectation of food systems was that they produced enough food to feed the world. When increasing production did not solve global hunger and health problems, food systems were expected to provide food and nutrition security. 1 https://foodsystems.community/food-systems-summit-compendium/ 2 https://nutritionforgrowth.org/tokyo-n4g-summit-2021-press-release/ 3 https://unfccc.int/process-and-meetings/conferences/glasgow-climate-change-conference-october-november-2021/outcomes-of-the-glasgow-climate-change-conference