Association between body mass index, multi-morbidity and activities of daily living among New Zealand nursing home older adults: a retrospective analysis of nationwide InterRAI data.

Being underweight was associated with a decline in the performance of ADL in nursing home residents. In contrast, being overweight and obese positively affected functional performance, demonstrating that the obesity paradox plays an important role in this population. The observed associations highlight areas where detection and management of underweight and healthy aging initiatives may be merited.