Malnutrition is common in the acute care setting. Despite the existence of a plethora of screening tools, many malnourished patients remain undiagnosed and untreated, in part due to competing responsibilities for screening staff, under- or over-referral to dietetics services, and inadequate dietetics resources. Better identification of patients at risk of malnutrition would enable optimised care provision and streamlined care pathways. This narrative review of reviews aimed to collate and synthesise literature documenting nutritional risk factors in adult hospital inpatients, to generate a comprehensive list of nutritional risk indicators from high methodological quality review articles. Six electronic databases were searched (Medline, Cumulative Index to Nursing and Allied Health Literature, Cochrane Database of Systematic Reviews, Joanna Briggs Institute Database, Embase and Scopus) using a systematic search strategy. Three researchers screened the resulting 5889 citations, identifying 59 reviews summarising original studies that investigated associations between indicators and measures of malnutrition, undernutrition or nutritional risk. After quality appraisal by two researchers, using the American Dietetic Association Quality Criteria Checklist for Review Articles, seven reviews were classified as high quality, identifying fifty-seven unique indicators of nutritional risk (disease status/condition – twenty-three; eating/appetite/digestion – twelve; type of diet – five; cognition/psychology/social factors – five; medication-related – two; miscellaneous – ten). This is the first comprehensive list of nutritional risk factors in adult hospital inpatients, derived from only the highest methodological quality reviews. This list contributes to the development of practice and evidence-informed systems-level approaches to the identification of nutritional risk in the acute care setting.