Food, health and the environment: towards a more sustainable diet

04 December 2013

201311 Sustainable Diet

On November 27, Professor Susan Jebb, Professor of Diet and Population Health at the University of Oxford's Department of Primary Care Health Sciences, gave the first annual lecture for the Oxford Martin Programme on the Future of Food. Hannah Rowlands considers the issues raised in the lecture, and the changes needed to make our diets sustainable.

The Oxford Martin Programme on the Future of Food was honoured to have Professor Susan Jebb present our first annual lecture. Professor Susan Jebb is a nutrition scientist, but recognises that dietary advice for consumers needs to optimise health within the constraints of a sustainable food supply.

The UK Food System

The food and drink industry is an incredibly important part of the UK economy, but in recent years much of its success has been predicated on producing and selling more and this underpins greater consumption of food. In theory, consumers could drive change, but they are generally insufficiently well-informed or motivated to prioritise long-term health and sustainability over and above the short term reward from food, so the food industry is further incentivised to produce abundant, cheap, popular foods, leading to the soaring burden of diet-related disease.

But food is not tobacco and it is possible to envisage a world where economic success is based on providing consumers with a healthier and more sustainable diet. This will require coordinated change on the part of business and consumers.

Our Food System is Unsustainable

There are supply-side pressures – resource scarcity, environmental degradation, climatic instability – and demand-side pressures – population growth, demographic change, changing diets – within the context of weak governance systems. This makes the issue of feeding 9 billion people by 2050 an enormous challenge.

Supply-side measures to meet growing demand include sustainable intensification and reducing food waste, the scale of which is a total scandal. But consumer demand is at least as important as supply side action. Changes to dietary habits have the potential to mitigate substantial greenhouse gas emissions.

A Sustainable Diet

The Livewell project sought to identify an eating plan which meets health goals, based broadly on the current EatWell plate, and delivers a 20% reduction in GHG emissions by 2020. The result is a diet with less meat, but more fruit and veg, and more bread and other ‘starchy’ foods.

Looking at health and sustainability reveals some clear synergies in the dietary changes required – for example, lower meat consumption, especially from ruminant sources, is associated with health benefits and will lead to global environmental benefits.

But there are also foods where the health and environmental impacts do not agree, such as sugar, which is associated with very low greenhouse gas emissions per calorie yet provides no other nutritional benefits beyond calories, which for many in the world are already in oversupply.

How to make dietary change happen?

Currently most interventions to change dietary habits are focused on health goals, but there may be lessons which inform dietary changes towards a more sustainable diet too.

Some examples of action to change diets include: food labelling, reformulation of products (eg. to reduce salt content), reductions in portion size to cut calories (you need to build public acceptability for this, otherwise the public think they’re getting ripped off with smaller portions for the same price), and food taxes (eg. on

Food Promotion

A large proportion of food is bought on promotion and interventions in store offer the potential to ‘nudge’ people to healthier and more sustainable choices. More generally, the wider social and cultural attitudes to food are shaped by factors such as food marketing and also influence what we buy. There is a debate about whether these factors can be changed through voluntary action by business or if regulation will be required.

We need to develop strategies specifically for environment-related actions, such as reducing meat, which the FCRN has been working on.


Coordinated change among consumers and business is vital to maximise progress towards a healthy and sustainable diet. Government must drive progress by taking a leadership role in setting out a long-term food policy which unites health, environment and economic goals. We also need better evidence and analysis of ‘what works’ from the academic community and stronger advocacy from respected voices among health professionals and the public health community. Civil society groups have an important part to play in making the public case for change and identifying acceptable interventions.

This is too hard for anyone to do alone, but if we work together, we can change the food system so that the path to a sustainable diet is easier for everyone.

Hannah Rowlands is Programme Co-ordinator for the Oxford Martin Programme on the Future of Food.

This opinion piece reflects the views of the author, and does not necessarily reflect the position of the Oxford Martin School or the University of Oxford. Any errors or omissions are those of the author.