Changes in malnutrition and quality of nutritional care among aged residents in all nursing homes and assisted living facilities in Helsinki 2003-2011.

•Prevalence of malnutrition increased among institutionalized older people over time.•Institutionalized population suffered more often from dementia and disability.•Dementia and disability explained the increase of malnutrition in these settings.•Number of positive developments were observed in the quality of nutritional care.•The quality of nutritional care could be improved by education of personnel.