Portrayals of young people as either victims or perpetrators of errant, aberrant or even dangerous attitudes, desires or behaviours may be criticised for obscuring the relations of power within which young bodies are socially and physically located. However, notions of ‘resistance’ to power within these critiques remain under-theorised. In this theoretical paper we take a new materialist approach to explore the affectivity of young bodies, and the flows and intensities that produce and reproduce power and resistance, and what young bodies can do, feel and desire. To illustrate young bodies’ resistances, we offer the example of the transgressive pro-ana movement that resists both biomedical and social definitions of anorexia. We conclude there is a need to focus upon ‘resisting’ as an affective movement of becoming, rather than upon ‘resistance’ as an agentic act, with consequences both for young bodies, theory, research and activism.