Maintenance of adequate nutrition in Head and Neck Cancer (HNC) patients is challenging. The rigours of radiation treatment and the burden of the malignancy make it difficult for HNC patients to maintain sufficient nutrition. In addition, HNC patients have higher levels of mental illness such as depression and anxiety and also higher levels of substance dependence, including alcohol misuse. It is therefore surprising that health behaviour interventions designed to improve nutritional status in HNC patients have not been evaluated. This trial aims to build on promising pilot data to evaluate for the first time a dietitian delivered health behaviour intervention (Eating As Treatment; EAT) to improve nutritional status among HNC patients.