Prevalence and prognostic significance of malnutrition in patients with cancers of the head and neck.

•Population-based cohort of head and neck patients (HNC) (N = 1756) in Alberta, Canada.•Weight loss (WL) absent in 42.9%, but WL present in 57% of new HNC referrals.•Predictors of WL included stage, dietary intake and performance status (P < 0.000).•WL Grade ((P < 0.000) and Dietary intake (P < 0.003) independently predicted survival.•WL history and dietary intake have high clinical utility in clinical practice.