Lifestyle Variation among the Elderly: Do Nutritional Knowledge and Diet Quality Differ When the Other Lifestyle Components Are Similar?

Older people's health is strongly determined by their lifestyle, and its deterioration is a cause for concern and calls for effective efforts to slow down the process. The aim of the study was to determine the relationship between diet quality and other non-food lifestyle elements. The data were collected in 2017 through a cross-sectional survey among 271 Polish elder citizens. A K-means cluster analysis was applied to separate homogeneous groups by lifestyle components (without diet) and a logistic regression was used to analyze the relationships between identified clusters and sociodemographic characteristics, nutritional knowledge and diet quality. Three homogenous clusters were identified, i.e., individuals with moderate physical activity and recommended sleep duration (pro-healthy), with low physical activity (low PA), and with short sleep (short sleep). Gender, age, education, place of residence, BMI, and health-promoting diet index (pHDI) did not differentiate adherence to clusters. The probability of being in the pro-healthy cluster increased with nutritional knowledge and declaring the same or better health status compared to peers, while it decreased when above-average financial status was reported. The obtained results importantly extend the previous findings by showing that the individual elements of lifestyle should be also perceived in the context of others. Further research focused on lifestyle as a whole might considerably support the implementation of multifaceted lifestyle interventions.