Abstract
Background: The Body Roundness Index (BRI) is an emerging anthropometric measure that reflects central adiposity, particularly relevant in ageing populations where body composition and nutritional status undergo significant changes. This study aims to explore patterns linking BRI values, age, energy intake, and micronutrient adequacy using cluster analysis, with a focus on implications for older adults. Methods: Data from 1504 community-dwelling older adults (mean age 74.4 ± 10.8 years) in Poland participating in the PolSenior project were analyzed. K-means cluster analysis was applied to standardized variables (BRI, age, energy intake, and micronutrient adequacy) to identify major participant profiles. Results: The data indicate that older adults, particularly those over 75 years old, are at an elevated risk of inadequate micronutrient intake, especially for essential nutrients such as calcium, magnesium, folate and vitamin D. Three distinct clusters were identified: Cluster 1 (n = 495, 33%): oldest participants, lowest BRI, and insufficient energy and micronutrient intake, indicating a high risk of undernutrition; Cluster 2 (n = 557, 37%): average age, moderate BRI, and highest energy and micronutrient intake, suggesting a potentially excessive energy balance. Cluster 3 (n = 452, 30%): the youngest group with the highest BRI and the lowest energy and micronutrient intake, indicating early-onset central adiposity and poor dietary quality. Conclusions: Three clusters were identified that differed significantly in BRI, age, and adequacy of energy and micronutrient intake. BRI combined with dietary indicators effectively distinguishes nutritional risk profiles among older adults. A low BRI may indicate a risk of undernutrition in advanced age, whereas a higher BRI with low nutrient adequacy suggests poor diet quality, even within the older population. Age-specific and nutrition-sensitive interventions are needed to support healthy ageing.