The idea of good nutrition also being sustainable is not a unique one, however the awareness around climate change has made people view good nutrition in a different lens.

Dietary interventions that are purported to assuage climate change generally tend to zero in on the reduction of dairy and meat consumption, however this must be analyzed further in the perspective of overall nutritional consequences for the general population. This raises the important question of can a diet that meets optimal nutrition requirements also provide protection to the environment?

So, what is a sustainable diet? There are no specific guidelines on what constitutes a sustainable diet but the general idea is it would take into account the impact an eating pattern has on the environment, the individual, and the food supply ecosystem as a whole. Factors that determine how sustainable a diet is may include: cost, biodiversity, ecosystem protection, nutritional availability (in the context of general health).

According to the EAT-Lancet Commission, vegan and vegetarian diets have the greatest reduction in land use and greenhouse gas emissions (GHGE). However, the implementation of sustainable eating is not as straight forward as replacing all animal foods with fruit & vegetables. The “diet for planetary health” that was published by the EAT-Lancet expert committee in 2019 was largely criticized, by the food industry as well as the medical and scientific community for not being culturally, socially, regionally or religiously sensitive and due to its potential to induce certain micronutrient deficiencies.

When it comes to the environment, for instance, if meat is replaced with plant foods while keeping the total dietary energy constant, the resultant diet could still have a higher GHGE. This is because, factors such as geographic region, farming techniques, transport method and growing conditions can all influence the environmental impact of foods.

In a nutritional perspective, any dietary change should be considered in terms of the overall diet, alongside any possible nutritional consequences for health. For example, dairy products or animal-based products serve as excellent sources of vitamin B12, generally absent in plants. Reduction of energy intake alone is also unlikely to reduce greenhouse gases, as the effect would be highly dependent on the types of food chosen, e.g. certain diets, that induce weight-loss tend to be low in carbohydrates and higher protein (animal foods tend to contain more bioavailable protein), are unlikely to reduce GHGE. Although interventions, like reducing processed meat consumption could be beneficial both for an individual’s health and the environment, there are other potential conflicts between health and environmental goals. Another such example is fish, which is often touted for its omega-3 content, however, overfishing/ farm-raising poses a serious threat to current fish stock.

So we return to the question, can one’s dietary lifestyle be both healthful and sustainable at the same time? Even though this is achievable, a deeper look at studies indicate that healthful diets may not necessarily be sustainable and the opposite is also true. While consumers are aware that food production has an impact on climate change, a lack of consumer knowledge of sustainable diets make them difficult to implement. It is therefore important to help consumers understand what constitutes a sustainable diet by communicating in a way that enables realistic behaviour change in the population.

According to The International Conference on Nutrition Rome Declaration, optimal diets, are ones that include traditional diets, that meet nutrient requirements across all age groups and special nutrition needs. Hence, like most questions when it comes to health, there is no “one diet that fits all”.

So, where does one start?
As providers, coaches or administrators, it is important to consider simple strategies of communicating all health information

Ask open minded questions and assess where the client or patient’s baseline is
Use teach back communication method to ensure clear understanding of the discussion
Use simple culturally and regionally relevant vocabulary
Use less words and more visuals

Food is unique as it satisfies both emotional and physiological needs. So, it is preferable to use a systematic and step by step approach to instill the feeling of progress even if not perfection. Let us protect individuals and our environment one concise and effective conversation at a time.