Aged care food service staff are being re-classified as personal care workers in a bid to stretch resources as facilities in the sector leave residents rife with malnourishment.
The insight comes after a study of more than 700 residents at 10 facilities in NSW, South Australia and Queensland revealed 32 per cent were malnourished and six per cent were severely malnourished.
United Workers Union's Aged Care Deputy Director, Catalina Gonzalez, said the conditions were compounded by aged care workers in food service being reclassified.
She said this was done in an underhanded effort by providers to boost the number of care time minutes counted in line with mandated care time allocated to residents.
"These moves on reclassification have the perverse effect of stretching responsibilities away from food preparation when in reality the roles should be solely based on much-needed quality of food preparation and service," Ms Gonzalez said.
The Monash and Griffith University research published in peer-reviewed journal Healthcare called for an urgent screening program as many aged-care providers lacked processes to detect the issue.
Lead author Jonathan Foo said malnutrition was a serious health issue associated with a higher risk of falls, infections, hospital admissions and death.
"One of the problems we see is that facilities don't even know who is malnourished in the first place, so they don't even know where to start," Dr Foo told AAP.
"We believe aged care facilities and the people we speak to on the ground really want to do the right thing.
"But there's just not an understanding of what malnutrition looks like, and by the time it's actually detected, it's usually too late."
The study is believed to be the biggest of its kind in Australia and comes three years after the Royal Commission into Aged Care Quality and Safety final report found residents were being served poor and unappetising meals that failed to meet nutritional needs.
Accurate data on the scale of malnutrition among the 193,000 people in care was not available, the research paper stated.
"What is surprising to me is that some of the changes that the government has initiated haven't been able to be implemented as well as maybe we would have hoped," Dr Foo said.
"A lot of these solutions are being given (from the) top down without a real understanding of what happens at the ground level and that's where speaking to people who actually provide the care, the residents and their families is so critical."
The authors said up-to-date data would hold providers to account to ensure they gave effective care.
In a statement, the federal government said it recognised the quality of food and nutrition remained a problem in the sector and was critical to maintaining good health.
It has committed $12.9 million across two years in the 2023 budget to improve the issue, including establishing an advisory support unit within the Aged Care Quality and Safety Commission.
This includes a food and nutrition hotline which has acted on almost 600 calls from residents, families and providers about food and nutrition in the past 12 months, a government spokesman said.
Laws and standards for the sector are also being strengthened.
National Seniors Australia chief executive Chris Grice said he was concerned by the findings and believed poor nutrition would be addressed under the government's proposed Aged Care Act.
"Any number is disturbing but to see it as high as that is very worrisome," he said.
"I'm sure both individuals and families in particular would be very concerned.
"Aged care is part of everybody's future and everybody has to play a role in making sure that we have a high-quality, successful aged care system.
"It's in everybody's interest for it to work."
Dr Foo and his colleagues are developing an automated malnutrition screening program that uses already collected data to help reduce the burden on facilities and workers.
