Malnutrition May Shorten Lives in Long-Term Care: A New Systematic Review Aims to Find Out

What if the difference between a longer life and an earlier death in a nursing home came down to something as basic — and as fixable — as what residents eat and drink? A team of Canadian researchers is betting it might. In a systematic review protocol published in Ageing International, Idrissa Beogo of the University of Ottawa and colleagues outline an ambitious plan to synthesize the evidence linking malnutrition to two of the most consequential outcomes in long-term care: the occurrence of new morbid events such as hospitalizations and pathological imbalances, and the length of stay — until death — of older people in long-term care facilities. The protocol, received in November 2024 and accepted in October 2026, sets the stage for one of the most comprehensive examinations of the nutrition and life expectancy nexus ever attempted in the sector.

The urgency behind the project is demographic as much as clinical. According to Statistics Canada, by 2050 nearly one in four Canadians — 24.9 percent of the population — will be aged 65 years or older. This shift presents major public health challenges, including ensuring adequate nutrition to support healthy aging and prevent nutrition-related adverse health outcomes among older adults. It is particularly true for the 6.8 percent of Canadians who reside in a long-term care facility, where the stakes of every meal are magnified by frailty, chronic disease and dependence on institutional food services. Despite the importance of nutrition at old age, the current literature, the authors note, puts emphasis on managerial aspects of eating and drinking — how mealtimes are organized, how dining rooms are staffed, how food is prepared — rather than on the hard clinical question of whether malnutrition actually shortens lives.

That gap matters because the biological case for concern is well established. Malnutrition in older adults is not simply a matter of being underweight; it is a syndrome involving inadequate protein and energy intake, unintended weight loss, low body mass index and diminished muscle mass that together erode physiological reserves. Research cited in the protocol shows that weight loss and low BMI are associated with increased mortality among nursing home residents, and that undernutrition still prevails in nursing homes despite decades of awareness. A 2026 systematic review and meta-analysis in BMC Geriatrics examined the incidence and associated factors of malnutrition among older people in nursing homes, underscoring how widespread and persistent the problem remains across settings. Hospital malnutrition, too, carries substantial costs — both human and economic — as documented in studies of hospital malnutrition prevalence and the economic cost of malnutrition in Europe.

The review’s design reflects the methodological rigor expected of modern evidence synthesis. It will include quantitative studies comparing Canada with Organization for Economic Co-operation and Development member countries, allowing the team to situate Canadian findings within an international context. Participants will include older people residing in any type of long-term care facility, and the analysis will take into account the type of facility, ownership status and participant characteristics — variables that matter enormously in a sector where ownership models range from municipal homes to for-profit chains. The protocol explicitly seeks to synthesize the evidence on the association between malnutrition and the occurrence of morbid events, such as new pathology, pathological imbalance and hospitalization, and the length of stay until death of older people in long-term care facilities.

The search strategy is correspondingly exhaustive. The team will query eight databases: Academic Search Complete, AgeLine, CINAHL, Cochrane CENTRAL, Embase, Food Science and Technology Abstracts, MEDLINE and Web of Science. The preliminary MEDLINE search strategy, reproduced in the protocol’s appendix, combines controlled vocabulary terms for nursing homes, homes for the aged, skilled nursing facilities and residential facilities with nutrition concepts spanning nutrition therapy, nutritional status, malnutrition, weight loss and feeding behavior, all intersected with geriatric and aged population terms and limited to studies published from 2010 onward. This layered approach — subject headings, title and abstract keywords, and population-specific terms — is designed to capture the full spectrum of quantitative evidence while minimizing the risk of missing relevant studies buried in the literature.

Methodological quality assessment will follow established tools. The protocol references the Newcastle-Ottawa Scale for assessing the quality of studies in systematic reviews, the revised Cochrane risk-of-bias tool for randomized trials, and AMSTAR 2, a critical appraisal tool for systematic reviews that include randomized or non-randomized studies of healthcare interventions. The team will adhere to PRISMA-P, the preferred reporting items for systematic review and meta-analysis protocols, and PRISMA-S, an extension for reporting literature searches. Peer review of electronic search strategies will follow the PRESS 2015 guideline statement, ensuring that the search itself withstands scrutiny. These frameworks, developed and refined over the past two decades, are what separate a credible synthesis from a cherry-picked narrative — and the authors’ adherence to them signals that the eventual findings will be built on transparent, reproducible methods.

The Canadian context gives the project particular resonance. The protocol has the merit, the authors write, of presenting the state of the nutrition and life expectancy nexus in Canadian long-term care facilities where underfunding is apparent. The sector’s struggles are well documented: studies of staffing levels and expenses in Canadian long-term care facilities by ownership status before and during the COVID-19 pandemic, analyses of who is looking after mom and dad among unregulated workers in Canadian long-term care homes, and the Ontario Long-Term Care COVID-19 Commission’s final report all point to structural fragility. Low staffing levels have been associated with malnutrition in long-term residential care homes, and longitudinal research has linked staff shortages and staff levels with health outcomes in nursing homes. Dietary service staffing, in turn, has been shown to impact nutritional quality in nursing homes — a chain of evidence connecting workforce to food to health.

The international comparison adds another layer of significance. A comparison of COVID-19 mortality rates among long-term care residents in 12 OECD countries revealed stark cross-national disparities, and OECD analysis of COVID-19 in long-term care documented the impact, policy responses and challenges across member states. By including OECD countries in the review, the team will be able to ask whether the association between malnutrition and life expectancy holds across different health systems, regulatory regimes and funding models — or whether it is modulated by them. The results, the protocol states, will inform the development of best practices and the formulation of nutrition policies, positioning the review as a direct input into policy rather than an academic exercise. Existing ESPEN guidelines on clinical nutrition and hydration in geriatrics provide a clinical foundation, but the protocol’s focus on facility type, ownership and participant characteristics could reveal how organizational context shapes nutritional outcomes in ways guidelines alone cannot address.

What makes the protocol potentially viral in its implications is the simplicity of its central question. Nutrition is one of the few modifiable factors in long-term care that touches every resident every day. If the synthesis confirms that malnutrition is associated with shorter stays and more morbid events — controlling for facility type, ownership and participant characteristics — the findings could reshape how governments fund food services, how facilities staff dietary departments, and how clinicians screen and intervene. If it does not, that too would be informative, redirecting attention to other drivers of health outcomes. Either way, the review promises to move the conversation from how mealtimes are managed to whether the food on the plate is literally a matter of life and death. The authors declare no competing interests, and no datasets were generated or analysed during the current study, as the protocol precedes the evidence synthesis itself. The full review, once completed, will be watched closely by gerontologists, dietitians and policymakers alike — because in a sector where 6.8 percent of Canadians live out their final years, the answer could not come soon enough.

Subject of Research: Association of Nutrition Services and Length of Stay/Life Expectancy in Long-term Care Facilities: A Systematic Review Protocol

Article Title: Association of Nutrition Services and Length of Stay/Life Expectancy in Long-term Care Facilities: A Systematic Review Protocol

Article References: Association of Nutrition Services and Length of Stay/Life Expectancy in Long-term Care Facilities: A Systematic Review Protocol. (n.d.). https://doi.org/10.1007/s12126-026-09682-8

Image Credits: AI Generated

DOI: 10.1007/s12126-026-09682-8

Keywords: Association, Nutrition, Services, Length, Stay, Life, Expectancy, Long-term, Care, Facilities, Systematic, Review