Severe and progressive weight loss is a feature of pancreatic cancer but it has been unclear whether dietetic intervention can improve patient outcomes. This study is a post hoc analysis of the extensive data available from the multicentre BH80 Cancer Cachexia trial to examine how patients with unresectable pancreatic cancer respond to intensive dietetic intervention. The BH80 study compared an n-3 fatty acid enriched oral supplement with an isonitrogenous, isocaloric supplement given over an eight week period. Additional qualitative data was also collected and examined for the patients recruited by the Australian sites. The aims were to determine whether achieving weight stabilisation is an appropriate goal of nutrition intervention for people with unresectable pancreatic cancer; to identify determinants of weight stabilisation; and to describe nutrition-related features of patients recruited by the Australian sites, prior to and during intensive nutrition intervention. Data from 107 patients for whom weight change data over an eight week nutrition intervention period was available, was divided into weight losing (less than 1kg lost) and weight stable (less than or equal to 1 kg lost) patients. Group survival duration (Kaplan Meier log rank test) and global quality of life (EORTC QLQ-C30 global health status/quality of life) were compared. Variables including energy intake, BMI, presence of pain, nausea and vomiting, and appetite loss, C reactive protein and stage of disease were also compared to determine predictors of weight stability using logistic regression analysis. This study demonstrates that weight stabilisation is not only achievable for some patients in the short term, but it is also associated with improved outcomes. Those patients who were able to stabilise their weight after eight weeks of oral nutrition support lived longer from baseline and reported better quality of life than those who continued to lose weight. Weight stabilisation is therefore a reasonable and worthwhile goal for this patient group.