The IPES-Food framework calls for closer attention to power relations across the levels of the global food system, and to feedbacks and cycles throughout the system. This article responds to this call with an account of how the purchasing and protest power of low-income consumers shaped and was shaped by local, national, and global food systems, through their responses to global food price spikes during 2007–12. Drawing on two multi-country mixed methods studies of how people adjusted to higher food prices and of food-related protests, the article identifies key common mechanisms through which people’s responses fed into larger processes of change. These include a sharp shift towards more precarious work, a greater reliance on markets and mass-produced and industrial foods, and an increasingly common set of grievances and protests about cost and quality, and about the responsibilities of public authorities to protect basic provisioning against the volatilities of the market.