Eating for health and sustainability

Greens horizon

Sometimes we make eating more complicated than it needs to be. The section of the Venn diagram where food, health and sustainability intersect, where we would all like to be, can seem impossible to reach. But when it comes to food, common sense is more useful than we realise. I have long been an advocate of a diet of seasonal fruit and veg, nuts and seeds, pulses and legumes, and a healthy scattering of treats. But now, a landmark study by Oxford University has proven that this is the best way to eat, for our health as well as for the planet.

Whilst studies like these are really helpful as a guide, it’s important to take an interest in the products you’re buying, as there is much more to consider. Consider the following questions: Am I eating too much of one thing? Where is this food from? Was it produced responsibly?

Much of the power we have to affect the climate crisis, and our health and wellbeing, comes from the food choices we make. A study by Oxford University, ‘On the multiple environmental aspects of food and health’, has linked the two, finding that healthy foods are almost always best for the environment, as well as best for us. The study found that poor diets threaten society by seriously harming people and the planet. Hopefully, this research can help inform better choices.

The researchers assessed the health and environmental impacts of fifteen foods common in western diets and found fruit, vegetables, beans and whole grains were best for both avoiding disease and protecting the climate and water resources. Conversely, eating red and processed meat excessively causes the most ill-health emissions and pollution.

There were a small number of foods that bucked the trend, however. Fish is considered by some a healthy choice but has a bigger environmental footprint on average than plant-based diets. High-sugar foods – such as biscuits and sweetened drinks – have a relatively low impact on the planet but are bad for health. So while environmental measures such as our carbon footprint and water use are important in considering food choices that are better for environmental health, we need to take a common-sense approach and create a balance of foods that benefit our own health too.
Of all the foods studied, a daily serving of processed red meat is associated with the largest increase in risk of mortality and incidences of coronary heart disease, type II diabetes, and strokes.

A sustainable and unsustainable diet can be made up of the following key areas:


  • Eating with a completely or predominantly plant-based approach
  • Eating a broad range of products and ingredients to support a diverse diet
  • Eating locally and seasonally
  • Supporting local communities and farmer community livelihoods when buying imported foods
  • Opting for lower-impact transportation for imported foods (for example, shipping rather than airfreighted food)
  • Choosing foods that have been produced sustainably, by farmers who protect natural resources and limit their chemical use


  • High intake of meat and dairy
  • Eating fish that are overharvested
  • Overreliance on a small number of foods
  • Relying on imported/air-freighted foods
  • Predominantly buying from large, industrial agricultural systems with little protection of workers and support for communities
  • Buying from farms which degrade soil and biodiversity, deplete water resources, routinely use chemicals and are intensifying climate change

Ultra-processed foods

Some food and drinks in the study did buck the trend. Fizzy drinks, an example of ultra- processed foods, are not resource-heavy in terms of planet health, but are extremely detrimental to human health.

Ultra-processed foods are foods that are altered so much that it can be hard to recognise the underlying ingredients. Made from cheap vegetable oils, flours, whey proteins and sugars, they are whipped up into something more appetising with the help of industrial additives and emulsifiers. Ultra-processed foods (or UPF) now account for more than half of all the calories eaten in the UK and US, and other countries are catching up fast.

Some UPFs, such as sliced bread or shop-bought cakes, may not seem ‘ultra’- processed to us. And that’s why most of us do not get through the day without consuming a UPF.

Here are some examples of UPFs: your morning bowl of cereal or a pot of flavoured yoghurt; crisps, blueberry muffins or vegan

hotdogs; a canned diet drink or a protein bar. When eaten on their own, once in a while, these foods are perfectly fine. But evidence now suggests that diets heavy in UPFs can cause overeating and obesity.

‘Consumers may blame themselves for overindulging in these foods, but what if it is in the nature of these products to be overeaten?’ says food writer Bee Wilson, in an article for the Guardian.

What to take from all this information?

I think it’s pretty much where I started at the beginning: eating is complicated. I try to eat as wide a range of fruits, vegetables, nuts, seeds, grains, flours, pulses and sweeteners as possible, thus maximising the variety of flavours, colours and nutrients that my body is exposed to. It’s like betting on every horse in the race and it helps to support smaller farms, organic producers and helps support biodiversity, too.

Things we can do

I want to make it clear that while I eat healthily almost always, I also feel strongly that eating is one part of our brilliantly fallible humanness. So there is always a place for a trashy chocolate bar or a bag of chip-shop chips.

Despite the trend-bucking exceptions I have mentioned above, the same dietary changes – eating more vegetables, legumes, whole grains – that could help reduce the risk of diet-related diseases could also help us meet crucial sustainability goals.

Click here for a link to the study.

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