Modification of Visual Contrast in the Dining Environment and Its Impact on Dietary Intake in Older Adults-A Systematic Review.

Background/Objectives: Malnutrition among older adults, particularly those in aged care, is a major contributor to morbidity and healthcare costs. Reduced visual contrast sensitivity, common with ageing and dementia, may impair the ability to distinguish food from tableware, potentially leading to decreased intake. This systematic review examined whether enhancing visual contrast in the dining environment improves dietary intake in older adults. Methods: Following PRISMA guidelines, five databases were searched from inception to March 2025. Studies were eligible if they involved adults aged ≥65 years and used visual contrast interventions (e.g., coloured tableware, lighting adjustments) aimed at improving food or fluid intake. A narrative synthesis was conducted, and study quality was assessed using the Mixed Methods Appraisal Tool. Results: Of 2901 records screened, four studies (five reports) met the inclusion criteria, involving a total of 64 participants. All studies implemented visual contrast enhancements, including high-contrast dishware and environmental modifications. Most reported increases in food or liquid intake, though statistical significance varied. Some studies also evaluated mealtime behaviours, functional abilities, and food waste, with mixed findings. Methodological limitations, including small sample sizes, short interventions, and inconsistent reporting limited the strength of evidence. Conclusions: Limited and low-quality evidence suggests a possible effect of modifying the dining environment to improve visual contrast for enhancing dietary intake in older adults, with visual contrast sensitivity, particularly those with dementia. However, the evidence gap is large and remains inconclusive. Future well-powered trials with standardised interventions and outcome measures are needed to determine whether these strategies can meaningfully reduce malnutrition in aged care settings.