Association between weight loss and food form in older individuals residing in long-term care facilities: 1-year multicenter longitudinal study

Changing the food form for older adults requiring nursing care from a regular to dysphagia diet is thought to impact their nutritional status. We assessed the association between changes in food form and weight loss over 1 year in older adults. Older adults residing in long-term care facilities in Japan (n = 455) who participated in the baseline (2018) and follow-up (2019) surveys were divided into two groups (regular diet, n = 284; dysphagia diet, n = 171). The regular diet group was further divided into the weight loss (n = 80; weight loss ≥5% over 1 year) and weight maintenance (n = 204; weight loss <5%) groups. After 1 year, the Barthel Index significantly decreased, and the proportion of participants who switched from a regular diet to a dysphagia diet significantly increased in the weight loss group than in the weight maintenance group. Multivariate logistic regression analysis found that Barthel index variation (odds ratio (OR): 0.97, 95% confidence interval (CI): 0.94-0.99), change from a regular diet to a dysphagia diet (OR: 4.41, 95% CI: 1.87-10.41), and body weight at baseline (OR = 1.06, 95% CI: 1.01-1.11) were significantly associated with weight loss. Our results suggest that maintaining the food form inhibits weight loss and improves health outcomes in older adults.