One in five residents of Canberra's nursing homes is malnourished.

One in five residents in Canberra's nursing homes are malnourished. Photo: Supplied

One in five residents of Canberra's nursing homes is malnourished, new research has found.

And symptoms of malnutrition are frequently confused for natural signs of ageing, according to the report by a Canberra academic.

Researcher Jane Kellett, a dietetics and nutrition lecturer at the University of Canberra, found 22 per cent of residents at Canberra nursing homes were either moderately or severely malnourished. Ms Kellett will present the research at the Dietitians Association of Australia's national conference in Canberra on Thursday.

A second report to be presented at the conference found that nearly half of older Australians receiving nursing care at home are malnourished.

Ms Kellett assessed 101 residents at five nursing homes for what she said was the first territory-based study of malnutrition in aged care facilities.

Residents volunteered for the study and were medically assessed for weight changes, dietary intake and the frequency of gastrointestinal symptoms such as nausea.

A physical assessment looked at their fat and muscle stores.

The ACT has just under 3000 people living in nursing homes and Ms Kellett found that 20 per cent of the residents she assessed were moderately malnourished and 2 per cent were severely malnourished.

Her report does not name the individual nursing homes used for the study. The research also excluded residents receiving high levels of medical care, or who had cognitive illnesses such as dementia.

"They were too unwell to participate and they're a high risk group and had they been included I think the statistics would have been higher," Ms Kellett said.

Similar studies in other states have found as many as half of residents of aged care facilities suffer from malnutrition.

Ms Kellett said that malnutrition in nursing homes, while not due to improper care, was too often mistaken as a symptom of ageing.

"They're very similar indicators and it's important malnutrition is recognised and not left untreated," she said.

"We need to recognise that malnutrition isn't part of ageing."

The dietetics lecturer said the causes were "multifaceted" and included factors associated with ageing, such as a reduction in skeletal muscle mass and body weight, as well as other possible limitations, including difficulty swallowing, reduced appetite, inadequate nutritional intake, depression and dementia.

Residents who participated in her study that were found to be malnourished were referred for medical attention and assistance from a dietitian or nutritionist.

Ms Kellett said study of malnutrition in Australia's ageing population was becoming more important as the number of Australians over the age of 65 grew. The number of Australians in that age group is expected to more than double in the next 30 years.

"Because that group is increasing, there's a lot of research on obesity but there's not a lot on malnutrition, which is probably just as important," Ms Kellett said.

"We've heard about hospital malnutrition for years but there isn't much research on malnutrition in residential aged care facilities.

"No one had done this in residential aged care in the ACT."