BACKGROUND: To ascertain the potential contributors to nutritional risk manifestation and to disclose the factors exerting a negative impact on hospital length of stay (LOS), by means of poor nutritional status, in a nonselected hospitalized population.MATERIALS AND METHODS: NutritionDay project questionnaires were applied to 295 adult patients. Study parameters included anthropometric data, demographics, medical history, dietary-related factors, and self-perception of health status. Body Mass Index (BMI) and Malnutrition Universal Screening Tool (MUST) were calculated for each participant. MUST score was applied for malnutrition assessment, while hospital LOS constituted the outcome of interest.RESULTS: Of the total cohort, 42.3% were at nutritional risk and 21.4% malnourished. Age, gender, BMI, MUST score, autonomy, health quality, appetite, quantity of food intake, weight loss, arm or calf perimeter (P < 0.001, for all), and dietary type (P < 0.01) affected nutritional status. Poor nutrition status (P = 0.000), deteriorated appetite (P = 0.000) or food intake (P = 0.025), limited autonomy (P = 0.013), artificial nutrition (P = 0.012), weight loss (P = 0.010), and arm circumference <21 cm (P = 0.007) were the most powerful predictors of hospital LOS >7 days.CONCLUSION: Nutritional status and nutrition-related parameters such as weight loss, quantity of food intake, appetite, arm circumference, dietary type, and extent of dependence confer considerable prognostic value regarding hospital LOS in acute care setting.