Inadequate energy and protein intake leads to malnutrition; a clinical disease not without consequence post acute hip fracture. Data detailing malnutrition prevalence, incidence, and intake adequacy varies widely in this patient population. The limited success of reported interventional strategies may result from poorly defined diagnostic criteria, failure to address root causes of inadequate intake, or errors associated with selection bias. This pragmatic study used a sequential, explanatory mixed methods design to identify malnutrition aetiology, prevalence, incidence, intake adequacy, and barriers to intake in a representative sample of 44 acute hip fracture patients (73% female; mean age, 81.7 ± 10.8 years). On admission, malnutrition prevalence was 52.2%. Energy and protein requirements were only met twice in 58 weighed 24 h food records. Mean daily patient energy intake was 2957 kJ (50.9 ± 36.1 kJ·kg(-1)) and mean protein intake was 22.8 g (0.6 ± 0.46 g·kg(-1)). This contributed to a further in-patient malnutrition incidence of 11%. Barriers to intake included patient perceptions that malnutrition and (or) inadequate intake were not a problem, as well as patient and clinician perceptions that treatment for malnutrition was not a priority. Malnutrition needs to be treated as a disease not without consequence, and food should be considered as a medicine after acute hip fracture.