Cancer cachexia is a complex, multifactorial syndrome that results from a reduction in food intake, a variety of metabolic abnormalities (including hypermetabolism) or more often a combination of the two. Multiple mediator pathways including pro-inflammatory cytokines, neuroendocrine hormones and tumour-specific factors are involved. Therapy requires a multi-model approach that addresses both reduced food intake and metabolic change. Combination treatments such as nutritional support plus metabolic/inflammation modulation promise improved functional capacity and quality of life.