Nutrition, Body Composition, and Functional Decline in Frailty

The global aging population is expanding at an unprecedented rate, bringing with it a rising burden of age-related syndromes that threaten independence, quality of life, and healthcare sustainability. Among these, frailty stands out as a complex, multidimensional clinical condition characterized by reduced physiological reserve, increased vulnerability to stressors, and heightened risk of adverse outcomes including falls, hospitalization, disability, and mortality. Frailty is not merely a consequence of chronological aging; rather, it reflects a progressive erosion of biological resilience driven by a constellation of interacting factors, with nutrition and body composition changes occupying a central and modifiable role.

Alterations in body composition are a hallmark of the frailty trajectory. The concurrent loss of skeletal muscle mass and strength alongside the redistribution and accumulation of adipose tissue, contributes substantially to the functional decline observed in frail individuals. These changes are compounded by shifts in bone mineral density, hydration status, and metabolic function, all of which interact dynamically with dietary intake and nutritional status. Malnutrition, micronutrient deficiencies, inadequate protein intake, and poor dietary quality have all been independently associated with accelerated frailty progression, yet the precise mechanisms through which nutritional factors drive or protect against functional decline remain incompletely understood.

Emerging evidence highlights the potential of targeted nutritional interventions, including optimized protein and amino acid intake, micronutrient supplementation, anti-inflammatory dietary patterns, and dietary counseling, to attenuate frailty-related body composition changes and preserve physical function. The Mediterranean diet, protein-rich supplementation strategies, and specific nutrients such as vitamin D, omega-3 fatty acids, and creatine have garnered growing interest in this context. Simultaneously, advances in body composition assessment tools are refining our ability to detect early changes and monitor the impact of nutritional interventions with greater precision.

Despite this progress, significant gaps persist. Standardized definitions of frailty, inconsistent diagnostic criteria for malnutrition, and heterogeneity across study populations make it challenging to draw firm conclusions and translate findings into clinical practice. Furthermore, the interplay between frailty, body composition, and nutrition is embedded within a broader context of physical activity, hormonal changes, gut microbiota composition, and chronic low-grade inflammation, all of which must be considered when designing effective prevention and treatment strategies.

This Research Topic aims to consolidate current evidence and stimulate novel inquiry into the nutritional determinants of body composition changes and functional decline in frailty. By bringing together interdisciplinary perspectives from nutrition science, geriatric medicine, exercise physiology, and clinical dietetics, this collection seeks to bridge the gap between mechanistic understanding and real-world application. The ultimate goal is to inform evidence-based nutritional guidelines that can meaningfully improve functional outcomes and quality of life in frail individuals across diverse clinical and community settings.

This Research Topic welcomes original research articles, systematic reviews, meta-analyses, narrative reviews, and clinical perspectives addressing the intersection of nutrition, body composition, and functional decline in frailty. Studies focusing on middle-aged and older adults, including community-dwelling individuals, outpatients, and those in long-term care settings, are particularly encouraged. We welcome articles addressing, but not limited to, the following themes:

• Nutritional assessment and screening in frail and pre-frail populations: tools, biomarkers, and clinical applicability.
• Protein and amino acid intake as modulators of muscle mass, strength, and physical performance in frailty.
• Micronutrient deficiencies (vitamin D, B vitamins, magnesium, zinc) and their role in frailty onset and progression.
• Dietary patterns (Mediterranean, plant-based, high-protein diets) and their association with frailty risk and body composition outcomes.
• Sarcopenic obesity and the nutritional strategies targeting concurrent muscle loss and fat accumulation in frailty.
• Gut microbiota, inflammation, and frailty: the role of diet in modulating the gut-muscle axis.
• Nutritional supplementation (omega-3 fatty acids, creatine, collagen peptides, leucine) and functional outcomes in frail older adults.
• Body composition assessment methods and their utility in monitoring nutritional intervention efficacy.
• Multicomponent interventions combining nutrition and physical activity for the prevention and reversal of frailty.
• Malnutrition and appetite dysregulation in frailty: prevalence, consequences, and dietary management.
• Hormonal and metabolic interactions with nutrition in the context of frailty and body composition decline.
• Sex and gender differences in nutritional needs and frailty trajectories.
• Clinical trials and real-world studies evaluating the efficacy and feasibility of nutritional interventions in frailty management.

Article types and fees

This Research Topic accepts the following article types, unless otherwise specified in the Research Topic description:

• Brief Research Report
• Case Report
• Classification
• Clinical Trial
• Community Case Study
• Conceptual Analysis
• Data Report
• Editorial
• FAIR² Data
• ... View all formats

Articles that are accepted for publication by our external editors following rigorous peer review incur a publishing fee charged to Authors, institutions, or funders.

Article types

This Research Topic accepts the following article types, unless otherwise specified in the Research Topic description:

• Brief Research Report
• Case Report
• Classification
• Clinical Trial
• Community Case Study
• Conceptual Analysis
• Data Report
• Editorial
• FAIR² Data
• General Commentary
• Hypothesis and Theory
• Methods
• Mini Review
• Opinion
• Original Research
• Perspective
• Policy and Practice Reviews
• Registered Report
• Review
• Study Protocol
• Systematic Review
• Technology and Code

Keywords: Frailty, Nutrition, Body Composition, Functional Decline, Sarcopenia, Malnutrition, Micronutrients, Nutritional Interventions

Important note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.