Canadians spend, on average, the last 11 to 12 years of their lives in poor health, representing 13.6% of their lifespan, notes registered dietitian and nutrition researcher Anne-Julie Tessier in the book Mange ta vie – Science, saveurs et santé, published by Éditions Cardinal earlier in 2026. Yet there is one determinant that could help people age in good health: what they put on their plates. 

“In Canada, among adults, diet is one of the most important modifiable risk factors for health, often ranking second only to smoking in terms of its contribution to the burden of disease,” she writes in the book, co-authored by actress Catherine St-Laurent, who contributes her recipes. 

Some cancers, cardiovascular diseases and type 2 diabetes, the expert points out, are not inevitable risks of aging. They can be the result of lifestyle and dietary habits. 

Living longer does not mean aging in good health 

Life expectancy in Canada has averaged around 81 years in recent years, according to Statistics Canada, rising from 81.3 years in 2022 to 81.7 years in 2023 and 82.16 years in 2024. In scientific research, however, a distinction is made between life expectancy and healthy life expectancy. 

A study by the federal agency, covered by the Insurance Portal last January, shows that Canadians are living longer, but this trend has not been accompanied by an increase in the number of years lived in good health. In 2023, for example, health-adjusted life expectancy (HALE), a measure that takes into account both longevity and health status, was 66.9 years at birth, compared with 68.6 years in 2020. 

Women, although they live longer, also spend a greater proportion of their lives in poor health, Statistics Canada notes. 

Health on your plate 

Anne-Julie Tessier is an assistant professor in the Department of Nutrition at the Université de Montréal, after completing three years of postdoctoral studies at Harvard. She is also a researcher at the Montreal Heart Institute. In her book, she therefore puts her area of expertise—the impact of nutrition on healthy longevity, particularly muscle and brain health—at the heart of the discussion. 

“The book presents the latest research on nutrition in the context of aging and health,” Anne-Julie Tessier told the Insurance Portal. “We cover four main areas: diet to promote long-term health and prevent chronic diseases, cognitive health, muscle health and mental health. Taken together, these four main areas represent what healthy aging is.” 

The true meaning of a ‘diet’ 

At a time when about half of adults have a waist circumference above Canadian thresholds associated with increased health risks, and weight-management medications are on everyone’s lips, the dietitian and researcher clarifies the meaning of the word “diet” in her book. 

“The word ‘diet’ does not refer to any restrictive eating regimen aimed at weight loss,” she writes. “For a scientist, a diet is an eating pattern, the collection of habits that characterize a person’s food intake. The word diet comes from the ancient Greek diaita, meaning art of living or way of life.” 

There is no universal definition, she says, of what constitutes a “good” diet, nor is there a single eating pattern that works for everyone. 

In her book, however, she summarizes several diets that have been scientifically shown to have positive effects on health: 

  • Mediterranean diet: based on olive oil, an abundance of fruits and vegetables, legumes and whole grains, as well as regular fish consumption. 
  • DASH diet: an acronym for Dietary Approaches to Stop Hypertension, developed by researchers in the 1990s to lower blood pressure (fruits and vegetables, whole grains, lean proteins, etc.). 
  • MIND diet: a hybrid of the Mediterranean and DASH diets, it emphasizes 10 food groups considered neuroprotective, such as leafy green vegetables, nuts and berries. 
  • Planetary health diet: focuses primarily on plant-based foods, legumes, whole grains and plant oils, with a smaller proportion of animal proteins, dairy products and added sugars. 

Up to an 86% greater chance of healthy aging 

At Harvard, Anne-Julie Tessier participated in the analysis of a study that followed 100,000 people for 30 years to compare four major dietary patterns. 

People “with the highest adherence to these diets had a 45% to 86% greater chance of aging in good health to age 70, without chronic disease and with good physical, mental and cognitive function,” she notes. 

“Our results suggest that the most beneficial patterns combine a high proportion of plant-based foods with moderate inclusion of healthy animal-based foods (fish or dairy products such as yogurt).” 

The ingredients of a healthy diet 

Adopting dietary patterns rich in plant-based foods, legumes, whole grains and high-quality proteins, with few ultra-processed foods, reduces the risk of developing major chronic diseases and, conversely, promotes muscle health, cognitive health, mental health and long-term health, Anne-Julie Tessier explains. 

Some of her findings: 

– In recent years, scientific evidence has accumulated in support of the Mediterranean and DASH diets for reducing the risk of cardiovascular disease and type 2 diabetes. 

– To preserve muscle health, it is preferable to consume at least one protein-rich plant- or animal-based food at each meal, including breakfast. 

– Fruits and vegetables are the pillars of a healthy diet for the brain, along with the consumption of fatty fish. 

– The Mediterranean diet has by far the most scientific evidence supporting its benefits for cognitive health. People who adhere to it most closely have up to a 30% lower risk of cognitive decline or Alzheimer’s disease. 

– One study shows that people who adhere most closely to the MIND diet have a 53% lower risk of developing Alzheimer’s disease, while moderate adherence to the diet is associated with a 35% reduction in risk. 

Coverage varies 

Access to advice from a nutrition professional may be available through employer benefit plans. Dietitian services are covered by many plans in Canada, including plans administered by insurers such as Sun Life, Manulife and Canada Life. Coverage, however, varies from one plan to another. 

Dietitians of Canada advocates for greater coverage of nutrition services through benefit plans. The Canadian professional association argues that these services can help manage health care costs. 

“Good nutrition and healthy eating can reduce the risk of certain health conditions that can lead to employee absences or high prescription drug use,” the association states on its website. “Employers should consider the role of nutrition services in reducing reliance on other health benefits.” 

Dietitians, the association says, can notably play a role in the prevention and treatment of type 2 diabetes, as well as in managing high cholesterol, hypertension and weight-related concerns. 

On this last point, actuarial and total rewards consulting firm Normandin Beaudry also notes that “obesity management in the workplace should go beyond drug coverage and leverage programs that promote overall health by focusing on nutrition, physical activity, psychological support and raising awareness around stigma.” 

On its website, the firm states that “facilitating access to professional services in mental health, nutrition and/or physical activity, while adapting internal practices and policies, can greatly influence employee health and thereby have a positive impact on productivity.” 

(With contributions to the content from Amélie Cléroux.)