Frontiers in Nutrition · Oct 12, 2026

Body weight-normalized resting metabolic rate and its associations with malnutrition and sarcopenia in hospitalized older adults: a cross-sectional study

By Jiang S, Zhao J, Chen P et al.

BACKGROUND: Malnutrition and sarcopenia are major contributors to frailty, functional decline, and mortality in older adults. Although the Global Leadership Initiative on Malnutrition (GLIM) criteria provide a standardized framework for diagnosing malnutrition, they do not incorporate physiological measures of metabolic function. We therefore investigated the associations of body weight-normalized resting metabolic rate (RMR/weight) with GLIM-defined malnutrition and sarcopenia in hospitalized older adults. METHODS: This cross-sectional study analyzed baseline data from a prospective cohort of hospitalized older adults who underwent comprehensive geriatric assessment (CGA) at Peking Union Medical College Hospital (PUMCH) between February 2024 and August 2025. Malnutrition was diagnosed according to the GLIM criteria, and sarcopenia was defined according to the Asian Working Group for Sarcopenia (AWGS) 2019 criteria. RMR was measured by indirect calorimetry and normalized to body weight (kcal/kg/day). Associations between RMR/weight and study outcomes were evaluated using multivariable logistic regression. Receiver operating characteristic (ROC) analysis was performed to assess the discriminatory ability of RMR/weight for malnutrition. RESULTS: A total of 141 participants (mean age, 74.8 ± 6.6 years; 54.6% women) were included, of whom 74 (52.5%) had GLIM-defined malnutrition. Both RMR and RMR/weight were significantly lower in participants with malnutrition than in those without malnutrition. After adjustment for age, sex, Charlson Comorbidity Index (CCI) score, and Katz Activities of Daily Living (ADL) score, each 1-kcal/kg/day increase in RMR/weight was associated with lower odds of GLIM-defined malnutrition [odds ratio (OR), 0.698; 95% confidence interval (CI), 0.597-0.816; p < 0.001] and sarcopenia (OR, 0.756; 95% CI, 0.658-0.870; p < 0.001). RMR/weight showed moderate discriminatory ability for malnutrition (area under the curve, 0.759; 95% CI, 0.677-0.838). An exploratory threshold of 20.5 kcal/kg/day yielded a sensitivity of 83.8% and specificity of 40.3%. Low RMR/weight (< 20.5 kcal/kg/day) was associated with higher odds of GLIM-defined malnutrition and sarcopenia, as well as with all three GLIM phenotypic criteria and several sarcopenia components. CONCLUSIONS: Lower RMR/weight was independently associated with GLIM-defined malnutrition and sarcopenia in hospitalized older adults. RMR/weight may provide complementary metabolic information regarding nutrition- and muscle-related impairment, although its clinical utility requires further validation.

doi.org/10.3389/fnut.2026.1914763Open accessPubMed 42936014Biomarkers