Well fed? The health and environmental implications of our food choices

By Hannah Rowlands

Last week, the Oxford Martin School hosted a seminar about the health and environmental imapct of our diets, as part of their seminar series "Health in the 21st century: what’s new?".

You can watch the seminar again on their website, but here are some notes that summarise the main arguments made by the three speakers.

Professor Susan Jebb

Susan’s opening comment was that she didn’t know if we were “well fed”, but that we are certainly “over fed” – she continued to explain the current burden of obesity. Specifically, that it’s not obesity itself that’s the problem, but that obesity is linked to an increase in the risk of disease and ill health.

A more positive take on the situation is to ask: “what difference would it make if we all ate a healthy diet?” Well, according to lots of research, we would see significant improvements in many health measures, such as cholesterol.

But change towards a nationally healthier diet is very slow, and that’s the greatest challenge right now.

And then when we think about the interaction between healthy eating advice and the environmental impact of our diets, the two are not always the same. For example, sugar is nutritionally not a great thing to eat lots of because of the increased risk factor for ill health. However, from an environmental point of view, sugar has a relatively low impact. It’s probably the most environmentally friendly way to get fat!

Tara Garnett

Before talking about the links between the health and environmental impacts of our diet, Tara reminded us that food connects us to everything – that food links people, the planet and society in many complex ways, not just health and environment.

The food system is estimated to account for around 30% of the world’s greenhouse gas emissions – importantly not just carbon dioxide but also methane and nitrous oxide, which are emitted from land use change and from cattle.

Food is also thirsty – accounting for most of the water used in irrigated land – and leads to biodiversity loss, where forest is stripped to make way for farmland.

There are several approaches to managing this problem:

  1. We can produce food differently - we can produce more food on the same land and with less environmental impact
  2. We can rebalance the system - change how the food system is governed, improve issues of equity and access to food, and reduce our food waste
  3. We can consume differently - move away from resource intensive foods

And it’s not an either/or situation – we need to be doing all of these approaches.

Is local food the answer? Not necessarily. You have to look at production methods and the efficiency of transport. It might be better to ship (by boat not plane) food from abroad if the local food is produced in an electrically heated greenhouse, for example.

Really, what we eat matters more than where it comes from. Most of the greenhouse gas emissions in the food system are from the farm, not from transportation or processing. And of all foods, the most greenhouse gas emissions come from meat, milk and eggs.

We need a diet with lower greenhouse gas emissions that is consistent with good health. This generally means a more diverse, balanced diet with more plants in it. Meat is eaten only sparingly, dairy in moderation, fish only from certified fisheries. Eat less highly-processed junk food and drink more tap water.

We also need to think about the other things that food gives us – how food makes us feel, what food makes us happy. A dreary diet that’s good for the environment is unlikely to be eaten by most people.

Mike Rayner

Mike began by explaining the problem with obesity, and then tried to explain how this problem arose, and finished with possible solutions.

He pointed out that obesity is not just an issue of individual food choices, but is an issue at larger scales too – the family, our communities and society in general. People don’t choose to be obese, there are other things affecting our individual food choices that lead to obesity. Also, our food choices don’t just affect us, they affect the people around us as well.

His explanation for obesity used a conceptual diagram with two axes – individual/group and objective/subjective. So, the individual subjective corner asks: “why am I fat?”, the individual objective corners asks: “why is he fat?”, the group objective corner asks: “why are they fat?”, and the subjective group corner asks: “why are we fat?”. These four areas give rise to explanations of obesity that are theological and philosophical, physiological and psychological, cultural and historical, and sociological and organisational.

And each of these explanations leads to its own suggestion for how to tackle the problem. For example, a physiological explanation of obesity – looking at energy intake – would suggest drugs as a solution. Psychology might suggest “nudge” as a solution. An economic explanation, which says that it’s the availability of high-energy foods that leads to obesity, might suggest a tax on sugary soft drinks. Lastly, a theological explanation that says “I’m just greedy” might suggest repentance as a solution!

Mike sees the problems of both obesity and climate change as symptoms of a more general issue of over-consumption. If we can find a solution that deals with that, then perhaps we can find a mutually advantageous solution to both of these huge problems.


Hannah Rowlands is the Coordinator of the Oxford Martin Programme on the Future of Food

Photo by Max Straeten

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