Seasonal variation in appetite status in adults aged 65 and older living alone and living with others: a four-season longitudinal study

Maintaining appetite in older adults is important for preventing malnutrition. Previous studies have shown seasonal variations in dietary intake, suggesting that appetite itself may vary with the seasons. Nevertheless, few studies have directly examined seasonal changes in appetite in older adults, particularly those living alone, who are at higher risk of malnutrition. Thus, the purpose of the present study was to identify when appetite declines throughout the year in older adults living alone and with others. Of the 60 adults aged 65 and older who participated in the study, 57 completed the longitudinal study over four seasons. Appetite for each season was assessed using the Simple Nutritional Appetite Questionnaire (SNAQ) and the visual analogue scale for hunger, satiety, and expectation of food intake. Nutritional status was assessed using the Mini Nutritional Assessment and the Food Frequency Questionnaire. The living arrangements of the participants were determined based on whether they were living alone or with others. The stratified analysis revealed seasonal changes in SNAQ scores exclusively among individuals living alone (<i>p</i> = 0.029, effect size = 0.280), who exhibited diminished appetite during summer compared to winter (<i>p</i> = 0.026, 95% CI: 0.076-1.258). No seasonal variation in appetite or nutritional status was observed in those living with others (<i>p</i> > 0.05). These findings highlight the importance of an approach that considers living arrangement and seasonality to ensure that older people maintain adequate appetite status throughout the year.