On the Path to Recovery: Optimizing Nutritional Care for Older Adults with Malnutrition and Sarcopenia from Hospital to Home

Malnutrition and sarcopenia frequently affect older adults, particularly during and after hospitalization, and are associated with impaired recovery, functional decline, and increased morbidity and mortality. Their coexistence can lead to a cycle of reduced nutritional intake, muscle loss, and dependency, often extending beyond hospital discharge. Despite increasing awareness, nutritional care remains suboptimal, fragmented, and inconsistently embedded within clinical practice. This thesis aimed to optimize nutritional care for older adults at risk of malnutrition and sarcopenia by identifying gaps in current practice, evaluating strategies to improve nutritional intake and recovery, and exploring directions for future research and implementation. In Part I, the focus was on identifying and understanding malnutrition and sarcopenia in hospitalized older adults. Chapter 2 evaluated the diagnostic performance of five commonly used malnutrition screening tools against the Global Leadership Initiative on Malnutrition (GLIM) criteria. Most tools showed limited sensitivity, resulting in 32–68% of malnourished patients remaining undetected. Chapter 3 analyzed national Dutch data from over 339,000 malnourished patients (2008–2019) and demonstrated that protein intake during hospitalization consistently remained below recommended levels, despite increased attention to malnutrition. Chapter 4 showed that decreased appetite is highly prevalent during and after hospitalization and is associated with poorer muscle strength and physical functioning. Together, these findings highlight that malnutrition and sarcopenia are underdiagnosed and undertreated. Addressing these issues requires a combination of improved diagnostic sensitivity, targeted nutritional strategies, and greater attention to patient-specific factors such as appetite and disease burden. Part II focused on developing and evaluating solutions for improving nutritional care. The ProIntens trial (Chapters 5 and 6) investigated an intensified, transmural dietetic care pathway aimed at optimizing protein intake and physical functioning during and after hospitalization. Although the intervention was feasible and well received, implementation was challenged by low inclusion rates due to patient burden, and by limited flexibility within the study design. These findings underscore the difficulty of translating nutritional guidelines into practice, particularly in vulnerable populations. The results further suggest that interventions are more effective when they integrate dietary support with physical activity, appetite management, and patient readiness. Chapter 7 presents a guiding framework for future nutrition research, emphasizing the importance of patient-centered, pragmatic, and adaptive study designs, as well as the integration of research into routine care. The framework outlines how future studies can balance methodological challenges with feasibility, ensuring that research outcomes are both scientifically strong and clinically meaningful. In Part III, the focus was broadened to additional nutritional determinants of muscle health. Chapters 8 and 9 present systematic reviews on the role of minerals in sarcopenia. The findings indicate that deficiencies in minerals such as magnesium, selenium, and calcium are associated with reduced muscle mass, strength, and physical performance. However, the available evidence is heterogeneous, and high-quality intervention studies are limited. These results suggest that optimizing micronutrient status may complement protein intake and physical activity in supporting muscle health in older adults. Overall, this thesis demonstrates that improving nutritional care requires a comprehensive approach that integrates early detection, personalized and multidisciplinary interventions, and implementation within real-world clinical settings. Malnutrition and sarcopenia remain underdiagnosed and insufficiently treated due to limitations in screening, fragmented care pathways, and practical barriers in implementation. Future efforts should focus on improving screening accuracy, embedding nutritional care into standard treatment pathways, and adopting flexible, implementation-oriented research designs. By bridging the gap between research and clinical practice, nutritional care can become a core component of recovery, ultimately supporting functional independence and quality of life in ageing populations.