Healthier food, healthier planet

As world leaders gather in Glasgow for COP 26, Nesta’s healthy life team and the Soil Association take a look at the impact our diet has on the health of both the planet and humans, and how we can move towards a food system that prioritises healthy and sustainable options for everyone.

Our diet is harming the planet

We are becoming increasingly aware that the food we eat and the systems that generate mass-produced, convenient and cheap products are harming the planet. A planet that we rely on to produce enough healthy food and safe environments for us all.

When talking about the links between our food and the environment, the focus is often on things like the impact of clearing land to raise cattle and the greenhouse gases this releases. However, the uncomfortable truth is that most of the systems behind our increasingly processed diets cause substantial damage to both local and global ecosystems.

How ultra-processed food affects our planet

The Soil Association recently published a report on the impact of ultra-processed foods on the planet, which concluded that ‘the abundance of ultra-processed foods in our diets is symptomatic of a sickly food system’. The ultra-processed foods that dominate our diets harm the environment in a number of ways. They typically rely on intensive industrial processes that harm natural biodiverse environments, and on cheap processed ingredients that harm our health. For example, palm oil and processed meats that replace whole foods on our plates and increase our calorie consumption.

How ultra-processed food affects our health

Ultra-processed foods now make up over 50% of shopping baskets in the UK, the highest in any country in Europe. Ultra-processed foods typically contain ingredients you wouldn’t use in your kitchen at home, including chemicals and colourings, preservatives, sweeteners and high levels of salt, fat and sugar.

There is a growing body of evidence that eating ultra-processed foods is bad for our health. Last year, three separate research groups reviewed the evidence linking ultra-processed foods to obesity. All three found that people who ate more ultra-processed foods were at higher risk of obesity and related conditions including type 2 diabetes and heart disease. In 2019, the first randomised controlled trial gave all participants unlimited access to meals with the same nutritional profile, but varied whether the food was ultra-processed or unprocessed. After just two weeks, participants eating ultra-processed food consumed more calories and their weight increased by about a kilo, while those eating unprocessed food ate fewer calories and lost a kilo.

As researchers learn more about ultra-processed foods, epidemiological and experimental studies increasingly show that their potential health risks extend far beyond their nutritional composition. This suggests it won’t be enough to reformulate ultra-processed products to remove calories or other targeted nutrients, we need to re-balance the diet towards fresh and minimally processed foods.

Climate change and obesity

Obesity is a complex issue driven by environmental, biological and social factors, and the food we eat is inextricably linked to the environment both locally and globally. In 2019, The Lancet medical journal- published a major report on the combination of three epidemics affecting the world: climate change, malnutrition and obesity. These epidemics are occurring at the same time and have similar underlying drivers, with complex consequences. The report calls for governments, institutions and industry to stop considering obesity in isolation to other major global challenges.

Worryingly, extreme weather, shifts in temperature and changes to rainfall will make it more difficult to grow the food we need for a healthy diet, like fruit and vegetables, and make them more expensive for food manufacturers and consumers. This is predicted to result in increased fresh food prices and could lead to more reliance on processed foods as they are primarily based on cheaper ingredients such as sugar, oils and preservatives.

Not only is this climate disruption likely to lead to catastrophic events such as crop failures, loss of biodiversity and famine, but it will lead to a rise in food insecurity. Research in the US found that adults experiencing food insecurity were more than 30% more likely to be obese than adults due to a need to rely on cheap, unhealthy options.

Sustainable food is the healthy choice

Healthy food choices are often also sustainable food choices. We know that our current reliance on ultra-processed food and production methods associated with it, is one of the biggest contributors to climate change, second only to energy production. Many of the interventions Nesta is exploring, such as the behavioural interventions we are testing to promote lower calorie options, could also be used to highlight sustainable food choices.

The EAT-Lancet Commission on food, planet and health sets out some suggestions for a healthy, sustainable diet: The Planetary Health Diet. A diet rich in fruits, vegetables and wholegrains, which focuses on proteins from plants rather than animals, is best for both planet and human health. Other studies, such as the ‘Ten Years for Agroecology’ report from sustainability think tank IDDRI, recognise the important role of ruminant animals in sustainable farming systems, but propose a similar direction of travel for dietary change. If we can reorient our diets around ‘less and better’ meat and ‘more and better’ plants, we’ll move towards a more sustainable and healthy model of eating.

However, to encourage consumers to shift to sustainable choices, these options need to be accessible and affordable. The National Food Strategy, published earlier this year, highlights that healthy food is three times more expensive per calorie than unhealthy, processed food. If we are to shift our food systems away from those that harm the environment and our health, these options need to be available to everyone.

Pollution and our bodies

Our food system is not the only area affecting our health, the air we breathe and the chemicals in our environments can also increase the likelihood of becoming overweight or obese. Over 80% of the global population live in environments that exceed WHO safe levels of air pollution and research suggests that air pollutants could contribute to weight gain. This could be due to pollutants causing fatty tissue to build up around organs, increasing the risk of chronic diseases or making people less likely to exercise outside.

The impact of air polluting chemicals is considered to be especially stark in children, with studies pointing to pollution slowing down children’s metabolisms and increasing inflammation, leading to unhealthy levels of weight gain.

What does this mean for the way we eat?

As we continue to explore how we can adapt our food environments to make the healthy choice the easy, affordable and appealing one, we must not waste this opportunity to ensure the healthy option is also the sustainable one and look for ways to reduce our food system’s impact on the climate. Achieving our aims will require joined-up action from governments across the world to help create a healthy and sustainable food system that everyone can access.

Nesta’s healthy life mission aims to reduce health inequalities and increase the years of healthy life lived in the UK by decreasing the prevalence of obesity. We’ll do this by changing food environments to make a healthy diet available, affordable and accessible to all. Achieving this goal relies on there being a sustainable food system which prioritises providing the foods we all need for a healthy diet, now and in the future.

The Soil Association is a charity with a mission to help everyone understand and explore the vital relationship between the health of soil, plants, animals and people, campaigning, educating and helping everyone to grow better together. They are the only UK charity working across the spectrum of human health, the environment and animal welfare. You can find out more about what the Soil Association are calling for from COP 26 here and join them at the Global Day of Action on 6 November.


Lucy Turner

Lucy Turner

Lucy Turner

Senior Analyst, A Healthy Lives mission

Lucy is an Senior Analyst on the 'A Healthy Lives' mission team.

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Rob Percival

Rob Percival is Head of Food Policy at the Soil Association, leading campaigns and advocacy in support of healthy and sustainable diets.