Sustainable diets aren’t just about our health and protecting the environment – they must include foods that are readily available, affordable, and acceptable to a community’s culture.
Although effects on health and the environment are important for many of us when doing our food shopping, our choices are also driven by availability, affordability, personal preference, social circumstances and cultural influences. We need to think about these aspects much more when assessing sustainable healthy diets, say the authors.
What is a sustainable food system?
A food system includes all the activities and outputs that relate to the production, processing, distribution, preparation and consumption of food.
The United Nations1 has recently described a sustainable food system as:
- Productive and prosperous (to ensure enough food)
- Healthy and nutritious
- Equitable and inclusive (to ensure that everyone has access to food and people working within the food system can earn a living)
- Respectful and empowering (to ensure people can make their own choices and get involved in shaping the food system)
- Resilient (to ensure enough food when shocks and crises hit)
- Regenerative (to ensure enough food now and for future generations).
Economic, social and cultural aspects of the diet are often overlooked
Designing a “global” sustainable healthy diet for everyone based on the science sounds like a great idea but there are challenges in the real world. There are lots of practical difficulties like differences in farming practices, access to foods and affordability.
We also shouldn’t underestimate the impact of cultural food habits which can be influenced by gender, religion and cultural beliefs. Culturally acceptable food habits don’t always provide a healthy or sustainable diet. People learn cultural food habits early in life but these habits can be modified by exposure to new types of foods, the food habits of friends and colleagues, and sociodemographic factors (eg, age, income, education).
The media also influences food habits and may be a good way of providing information on sustainable healthy diets and supporting dietary change. Greater understanding of how food acceptability and sustainability awareness influence people’s food choices would help in the development of culture-specific plans to build trust, change mindsets and shift food habits toward healthier and more sustainable diets.
Tensions and trade-offs
To achieve healthier and more sustainable diets some trade-offs across the four dimensions of sustainability (health, society, economics and the environment) may need to be made.
Improving access to affordable nutrient-rich foods across the world is a major sustainability goal. But nutrient-rich foods are often expensive and they may have a high carbon footprint. Lower-cost diets that are culturally acceptable may provide plenty of calories but not enough nutrients.
Animal-sourced foods like meat and dairy are examples of sustainability trade-offs. They are nutrient-rich foods, but they have a high environmental impact because animals produce methane gas and animal husbandry makes demands on water, land and energy supplies. From a social point of view, livestock generate income and may also have other important social, cultural and economic value, especially in low- and middle-income countries.
Tensions and trade-offs need to be carefully assessed when trying to improve access to sustainable healthy diets. It is important to include social and economic perspectives alongside scientific and practical considerations in bringing about dietary change, say the authors.
‘Although sustainable diet research has focused on health and the environment, the social and economic dimensions of sustainable diets and food systems should not be forgotten.’ – Nicholls and Drewnowski, 2021.