By Pamela Mason

How can huge populations be fed sustainably – healthily, equitably and affordably – while maintaining the ecosystems on which humanity depends? In a new book I have co-authored with Professor Tim Lang from City University, we explore this very big question. The evidence of diet’s impact on public health and the environment has grown in recent decades, yet changing food supply and consumer habits proves hard with policy makers hesitant to reshape public eating habits.

Although it has traditionally been assumed that food production and consumption can look after themselves or be left to the open market, human activity across the food system is driving a mismatch between humans and the planet. While this mismatch is recognised, there is wide debate as to what to do about it. Much focus to date has been on food production and how that can be made more sustainable. Such effort needs to continue, but in this book, we focus on the demand side and what sustainable diets would look like.

Sustainable diets are often considered to be those that are good for the environment and hence low in carbon. However, we propose a multi-criteria approach to sustainable diets, giving equal weight to the environment, nutrition and public health, socio-cultural issues, food quality, economics and governance. This six-pronged approach to sustainable diets brings order and rationality to what either is seen as too complex to handle or is addressed simplistically and ineffectually.

In practical terms a sustainable diet means food that is culturally accessible, affordable and nutritionally adequate, and also respectful of biodiversity and ecosystems. Quite simply it’s a good diet. Globally, this will mean a diet with a high intake of vegetables, legumes, fruit and grains. For people in wealthy countries who enjoy meat, it will mean eating less but better, and for people in poorer countries whose diets may be based on staple carbohydrates with little or no meat, it may mean eating more.

Our rationale in the book for reducing meat consumption globally is that meat is increasingly produced on an industrial scale which relies heavily on feeding grain, often imported grain, to livestock. Globally, 36% of the calories produced by the world’s crops are used for animal feed, and only 12% of those feed calories ultimately contribute to the human diet as meat and other animal products. With growing numbers of people to feed, this is not a good use of land.

That said, and of relevance in Wales with its significant concentration on livestock farming, it is true that well-managed animal grazing, especially on the uplands, can be compatible with carbon sequestration in soils. But whether or not livestock production is environmentally viable depends on the extent to which it is integrated into ecosystems, landscapes, farming systems and livelihood activities. This is a challenge for farming, but appropriate support and the will to change where necessary could help to shift livestock production in a more sustainable direction.

However, more regenerative livestock farming should not deflect us from the dietary changes that are needed, in particular for more vegetables and legumes, which will require more horticulture and support for production and indeed consumption. In this context, the Food Foundation’s Peas Please initiative aims to bring together farmers, retailers, fast food and restaurant chains, caterers, processors and government departments with a common goal of making it easier for everyone to eat vegetables.

What we argue for in this book is the need for sustainable dietary guidelines at a national and local level to provide a framework for a transition in food systems. While the UK Eatwell Guide, revised in 2016, is a good step forward in providing guidance on healthy, sustainable diets, only Sweden, Germany, Brazil and Qatar have so far been clear about helping their citizens to change their diets in significant ways. In Wales, policy could help to shift the food system to deliver better quality food, accessible to everyone, delivering health for people and the environment, fairness for producers and all who work in the food system, with rounded economics and trusted governance. Sustainable dietary guidelines would help everyone in the food system to do what needs to be done for the benefit of future generations of people across Wales.

You can order Sustainable Diets: How Ecological Nutrition Can Transform Consumption and the Food System, by Pamela Mason and Tim Lang, from this link.