Canadians can expect to live well beyond the age of 80 thanks in large part to good nutrition. A study published Monday in the Canadian Medical Association Journal looks at what happens to those who suffer from what experts call 'food insecurity.'

Food insecurity is defined as inadequate access to food because of financial constraints. Statistics Canada and the Canadian Community Health Survey estimate that one in eight households in Canada is food insecure.

That means four million Canadians live in homes that have difficulty putting food on the table, including close to 1.2 million children. Across the planet, an estimated 800 million people have food insecurity, according to the World Food Program.

Postdoctoral fellow Fei Men and Prof. Valerie Tarasuk at the University of Toronto's Department of Nutritional Sciences and colleagues used data from the Canadian Community Health Survey. It collects health information on half a million Canadian adults. The researchers compared longevity in people with food security to those who are marginally, moderately or severely food insecure.

Between 2005 and 2017, 25,460 people had died prematurely. Those identified as food insecure were between 11 and 37 per cent more likely to die prematurely.

In absolute terms, being food insecure took nine years off a person's lifespan.

Why most people died prematurely

What makes the study interesting is that the researchers were able to determine the likely causes of death associated with food insecurity. The study found that severe food insecurity was associated with mortality from cardiac and respiratory diseases as well as diabetes.

The authors said that the material deprivation and psychological distress caused by food insecurity causes chronic inflammation, which leads to chronic disease.

Other studies have found that the incidence of such chronic diseases is higher in people with food insecurity, so the link between food insecurity and excess mortality from these conditions is plausible.

The study also found that food insecurity also increases the risk of death from infectious diseases such as HIV and hepatitis C. People who were food insecure in the study were also more likely to die by unintentional injuries as well as self-harm. Food insecurity has also been linked to mental health disorders and substance use.

Keys to live well

Possible fixes for food insecurity aren't complicated.

Studies have shown that seniors with a guaranteed annual income had better self-reported health, functional health and self-reported mental health.

The U.S. has the Supplemental Nutrition Assistance Program or SNAP, a program once known as the food stamps program. SNAP provides roughly $2 (Canadian) per person per meal. SNAP has been shown to reduce food insecurity by 30 per cent with even better results in vulnerable populations such as children and households where meals are often skipped for due lack of money. SNAP participants report excellent or very good health.

Access to SNAP among pregnant mothers and in early childhood improve birth outcomes and long-term health as adults. SNAP helps seniors live independently and avoid hospitalization.

Another approach is to encourage green grocers to set up stores in low-income neighbourhoods where otherwise residents have little alternative but to use variety stores and fast-food restaurants.

The focus of the study is food insecurity but at root it's about the health problems and mortality associated with poor nutrition. Reversing malnutrition by shoring up food security improves health dramatically.

Once again, it's not medical breakthroughs but what many of us take for granted that bring the biggest bang for the buck. In this case, it's nutritious food, but secure housing, exercise, vaccinations, social networks and other socioeconomic determinants of health are the keys for all of us to live well.

The cost of providing adequate nutrition for all regardless of ability to pay is a smart investment that would save a lot more money in health-care spending down the road.