AIM: Weight loss is among the diagnostic criteria for frailty and is associated with increased mortality among older people. This study aimed to identify factors associated with future weight loss among community-dwelling older people. METHODS: A multidimensional questionnaire-based prospective cohort study was carried out. The questionnaire included the Kihon Checklist, instrumental activities of daily living (IADL) scale, Activity Scale for the Elderly, Fall Risk Index-21 and Dietary Variety Score. The associations among the scores of the scales and the 3-year weight change from study entry were assessed. The participants were categorized into the non-weight loss group, <
4.5-kg weight loss group and >
4.5-kg weight loss group. RESULTS: In total, 982 participants completed the follow up. Their mean age was 73.4 ± 5.1 years, and 545 (55.5%) participants were women. Among the IADL questionnaire subitems, depositing and withdrawing money from the bank, walking, interacting with people, taking medication, and cooking were associated with 3-year weight loss. Furthermore, cooking was strongly associated with weight loss. However, there was no association between eating frequency and weight loss. Finally, low IADL and physical function scores were associated with a doubled risk of future weight loss. CONCLUSIONS: An association was found between 3-year weight loss and physical fitness and IADL, such as walking, among community-dwelling older people. Future weight loss in older people can be caused by a decline in IADL and physical fitness before a decline in dietary intake. Furthermore, maintaining IADL and physical fitness can prevent future weight loss and frailty. Geriatr Gerontol Int 2025
25: 418-424.