As obesity rates increase worldwide, healthcare providers require methods to instill the lifestyle behaviours necessary for sustainable weight loss. Designing effective weight-loss interventions requires an understanding of how these behaviours are elicited, how they relate to each other and whether they are supported by common neurocognitive mechanisms. This may provide valuable insights to optimize existing interventions and develop novel approaches to weight control. Researchers have begun to investigate the neurocognitive underpinnings of eating behaviour and the impact of physical activity on cognition and the brain. This review attempts to bring these somewhat disparate, yet interrelated lines of literature together in order to examine a hypothesis that eating behaviour and physical activity share a common neurocognitive link. The link pertains to executive functions, which rely on brain circuits located in the prefrontal cortex. These advanced cognitive processes are of limited capacity and undergo relentless strain in the current obesogenic environment. The increased demand on these neurocognitive resources as well as their overuse and/or impairment may facilitate impulses to over-eat, contributing to weight gain and obesity. This impulsive eating drive may be counteracted by physical activity due to its enhancement of neurocognitive resources for executive functions and goal-oriented behaviour. By enhancing the resources that facilitate ‘top-down’ inhibitory control, increased physical activity may help compensate and suppress the hedonic drive to over-eat. Understanding how physical activity and eating behaviours interact on a neurocognitive level may help to maintain a healthy lifestyle in an obesogenic environment.