Reframing Dietary and Nutritional Interventions for People with Dementia

In people with dementia, malnutrition and dehydration are strongly associated with declines in physical function, increased susceptibility to infection, delirium, worsening behavioral and psychological symptoms of dementia (BPSD), and earlier hospitalization and institutionalization. Epidemiological and clinical studies in older adults and people with dementia consistently demonstrate that adequate intake of energy, protein, and fluids does not treat dementia itself, but plays a critical role in suppressing reversible factors that can rapidly exacerbate disease progression.However, many conventional nutrition education and dietary interventions implicitly assume cognitive abilities such as self-management of food intake, understanding of nutrients, and judgment in food selection. For people with dementia, these assumptions often render implementation and continuation difficult. As a result, an “implementation gap” emerges in which theoretically valid nutritional interventions fail to function effectively in real-world clinical and caregiving settings.The purpose of this paper is to reconceptualize dietary and nutritional interventions for people with dementia by systematically separating (1) core active ingredients from (2) elements that generate excessive cognitive and operational burden. By integrating existing guidelines, intervention studies, and clinical epidemiological research, we propose an implementation-adapted minimal model consisting of: (1) ensuring one protein item at each meal, (2) daily fluid intake of 1.2–1.5 liters, and (3) meal environment design that does not require choice or judgment.This model does not aim to directly modify the neurodegenerative pathology of dementia. However, by suppressing “progression accelerators” such as malnutrition, dehydration, infection, delirium, and BPSD, it offers high practical utility for both clinical practice and long-term care policy.