About a third of seniors are at risk of being undernourished, according to Statistics Canada.

The results of the survey suggested 34 per cent of Canadians aged 65 or older were at nutritional risk, the agency said in its report Wednesday.

"Nutrition is a building block for optimal health," report author Pamela Ramage-Morin said in Ottawa. "We know that undernourishment can lead to falls, it can lead to hospitalization."

Ramage-Morin said the goal is to identify seniors at risk of malnourishment before they reach that stage.

In the study, gaining or losing more than 10 pounds (4.5 kilograms) in the past six months and skipping meals almost every day were the main drivers of nutritional risk.

Eating alone, financial constraints and lack of help with shopping and cooking may contribute to nutritional risk among seniors. (Srdjan Ilic/Associated Press)

Many factors affect the type of food older Canadians eat, including how often they shop, how difficult it is to cook, difficulty swallowing, and how much money they have to spend.

Depression and loneliness can also be factors, especially for women aged 75 and older, the agency said. Those taking medications or who were disabled were also at risk, after taking age and level of education into account.

Women were more likely than men to be at nutritional risk at 38 per cent versus 29 per cent.

Previous Canadian research suggests nutritional risk could be more common when counting vulnerable populations such as those living in nursing homes or receiving support from community agencies.

George Parsons works at the George Street United Church in St. John's, which offers free activities and a meal for seniors.

"We found where there was two in a family, there was a greater tendency that they would cook versus somebody living alone that probably would get up and maybe even skip an entire meal," Parsons said.

The report was based on the 2008-2009 Canadian Community Health Survey on health aging, which covered those aged 45 or older living in the 10 provinces.

Those living on reserves, full-time members of the Canadian Forces, residents of collective dwellings and those who were institutionalized were excluded.

With files from CBC's Terry Reith and Vik Adhopia