Ma LX, Taylor K, Espin‐Garcia O, et al. - Whether malnutrition and sarcopenia have prognostic utility in de novo metastatic gastric and esophageal (GE) adenocarcinoma, was determined. Participants were patients with de novo metastatic GE adenocarcinoma examined at the Princess Margaret Cancer Centre from 2010 to 2016, who had a pre‐treatment abdominal computed tomography available. There were 175 consecutive patients in total, of those, malnourished and sarcopenic at baseline were 33% and 39%, respectively. Significantly shorter overall survival was experienced by patients with pretreatment malnourishment. Worse overall survival (OS) was noted in patients who became malnourished during chemotherapy vs those who maintained their nutrition. ECOG, pretreatment nutritional risk index (NRI) and alteration in NRI were identified as significant prognostic factors for OS, while sarcopenia was not, in patients with de novo metastatic GE adenocarcinoma. Beneficial prognostic information can be gained by using NRI at baseline as well as during treatment.