The typical Western diet with its heavy reliance on animal and processed foods, and insufficient whole plant foods, is driving our epidemic of non-communicable diseases globally. The current level of chronic disease and its management are simply not sustainable, as evidenced by our burgeoning healthcare costs individually and as a society.  According to the Global Burden of Disease Study, suboptimal diet is responsible for more deaths globally than any other risks, including tobacco, with most of these deaths due to cardiovascular disease, followed by cancer and type 2 diabetes (1). Improvement of diet could potentially prevent 1 in 5 deaths. Top dietary risks identified were high intake of sodium (reflecting our reliance on processed food), and low intake of whole grains, fruits, nuts and seeds, and vegetables. Clinical and country specific guidelines are now catching up to the medical literature and are incorporating plant-based diets into clinical practice guidelines for the prevention and management of chronic disease. The 2019 Canada Food Guide is an excellent example of this, with its food plate being at least 87.5% plant-based. Greater adherence to the Canada Food guide has been shown to significantly reduce the risk of cardiovascular disease (2). 

The position statement on vegetarian diets by the Academy of Nutrition and Dietetics states that appropriately planned vegetarian, including vegan, diets are healthful, nutritionally adequate, and may provide health benefits for the prevention and treatment of certain diseases (3). These diets are appropriate for all stages of the life cycle, including pregnancy, lactation, infancy, childhood, adolescence, older adulthood, and for athletes. They note that vegetarians and vegans are at reduced risk of certain health conditions, including ischemic heart disease, type 2 diabetes, hypertension, certain types of cancer, and obesity. 

Promoting plant-based nutrition at all stages of life can help prevent, manage and in some cases reverse non communicable diseases and support a more equitable and sustainable health system.

Animal agriculture is the leading cause of antibiotic resistance, which has been declared one of the top ten public health threats facing humanity by WHO. It is a leading cause of death, associated with close to 5 million annual deaths globally.

In 2018, an estimated 14,000 Canadian deaths were associated with antimicrobial resistant bacteria and cost our healthcare system $1.4 billion (4). Most antibiotics in Canada are used at farms not hospitals. In 2020, 82% of antimicrobials were sold for use in production animals, 17% for people, < 1% for cats and dogs and < 1% for plants/crops. Medically important antimicrobials sold for use in production animals in Canada is 3 times the quantity reported by European countries. (Canadian Antimicrobial Resistance Surveillance System (CARSS) Report 2022). Pandemic risk is another alarming bi-product of our industrialized food system, with ongoing global outbreaks of swine and bird flus, requiring culling of millions of animals in attempts to limit spread of the infectious diseases (5).

 Global food production is responsible for 35% of all greenhouse gas emissions (GHGE), with the use of animals as a source for food, as well as feed for farmed animals, responsible for almost 60% of all food production emissions. Seminal research by Poore and Nemecek (2018) which compiled data from life cycle assessments in 570 published papers covering 38,700 commercial farms across 119 countries, representing 90% of all food products, showed that beef and dairy had the greatest GHGE and land use impact (6).

A global shift to a plant-based diet would reduce GHGE from food by about 50%. Eliminating beef alone would reduce GHGE by 33%. Even the lowest-impact animal products have a much higher impact than plant sources of protein. Of note, about 85% of GHGE is at the production phase, so while buying local is important, which food we choose to eat is far more impactful in reducing our climate footprint.

To have any hope of meeting the central goal of the Paris Agreement, which is to limit global warming to 2°C or less, our carbon emissions must be reduced considerably, including those coming from agriculture. Clark et al. show that even if fossil fuel emissions were eliminated immediately, emissions from the global food system alone would make it impossible to limit warming to 1.5°C and difficult even to realize the 2°C target (7). Thus, major changes in how food is produced are needed if we want to meet the goals of the Paris Agreement. 

Although we often focus on GHGE, the global food system, particularly animal agriculture, has a broader impact on planetary health (8). Animal agriculture is the biggest driver of wildlife and biodiversity loss, species extinction, freshwater use, water pollution and ocean destruction (9). 

Half of all habitable land is used for agriculture, 80% of which is used for animal agriculture which only supplies 18% of global calories. Land use change, mainly land conversion for crop production, raising farmed animals and plantations is the strongest driver of our destruction of nature. Transitioning to a plant-based food system will free up to 75% of land that can be used for rewilding (10).

In 2019 the Eat Lancet commission produced their landmark work with the global planetary health diet, a reference diet that will keep the food system within planetary boundaries whilst improving human health and preventing an estimated 11 million deaths globally per year. It is a predominantly plant-based diet with animal foods considered to be optional and if consumed, contributing about 13% of energy intake (11).

The single biggest lever we can use as individuals and institutions, for individual health and to mitigate planetary destruction, is to promote plant-based nutrition at all levels including for our in-patient hospital food, in our canteens and food services, at our conferences, rounds, and healthcare events (12,13,14,15,16). The latest IPCC report states ‘reduction of excess meat consumption is amongst the most effective measures to mitigate GHG emissions with a high potential for environmental health, food security, biodiversity and animal welfare co-benefits’. Healthcare professionals and systems have a powerful opportunity to be leaders in nourishing the health of their people and the planet on which we depend (17, 18, 19).