Dietary intake characteristics in older adults: A systematic review of physical, social, psychological, and behavioral limitations

• This study reviewed the factors limiting dietary intake in older adults. • The study aimed to gain insights into unintentionally unhealthy eating habits. • Poor oral function reduced meat, fish, legume, vegetable, and fruit intakes. • Few studies clarified the association of other factors with nutrients or foods. • Further research on the link of multifactorial limitations with diet is needed. Older individuals generally have decreased food intake owing to physical, social, psychological, and behavioral limitations. However, the characteristics of food and nutrient intake resulting from these limitations are poorly organized. Organizing knowledge for practical application in older adults is necessary when considering nutrition care strategies. This review aimed to characterize food and nutrient intake according to these exposure factors in older individuals. This systematic review followed the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines (PROSPERO, CRD42024582151). MEDLINE and Web of Science were searched in September 2024 using the following inclusion criteria: community-dwelling older adults aged ≥65 years (participants); factors contributing to physical, social, psychological, or behavioral limitations affecting food and nutrient intake (exposure); food and/or nutrient intake, dietary patterns, and overall diet quality (outcomes); and cross-sectional and cohort studies (study design). Among the 2,354 studies screened, 29 studies were analyzed. These included studies addressed the following exposure factors: oral function and physical activity (physical); economic status, marital status, household size, and educational attainment (social); depressive symptoms (psychological); and food security, nutritional knowledge, and cooking skills (behavioral). Reduced oral function was associated with lower intakes of meat, fish, legumes, vegetables, and fruits. Low economic status and educational level were associated with poor diet quality. However, there was limited research characterizing the dietary intakes of individuals with other factors, such as poor cooking skills or decreased sense of taste and smell. Further research is needed.