You probably already know that processed foods can damage your health, but there is another cost: their impact on the planet. Unfortunately, these foods are convenient, tempting, and absolutely everywhere. In fact, ultra-processed foods make up 56 per cent of the average diet in the UK.
So, what does ‘processed’ actually mean, what’s the cost to our planet, and what can you do about it?
What is processed food?
Foods are split into four main groups:
1. Unprocessed and minimally processed. These are raw ingredients, like fruit and veg, nuts and seeds, pulses, or fresh eggs, milk, and meat. Minimally processed foods have gone through a process such as drying, crushing, freezing, boiling, or pasteurisation, but contain no added ingredients. Think frozen veggies or fish, pasteurised milk, plain yoghurt, dried spices, or fresh juice.
2. Processed culinary ingredients. These foods are not designed to be eaten alone, but are used to prepare dishes with the foods in group one – e.g. oils, butter, sugar, salt, and vinegar.
3. Processed foods. These are usually made by mixing group one and two ingredients, to prolong the food’s life or enhance its flavour. Examples include cheese, smoked or cured meat, beer or wine, salted or sugared nuts, or tinned fruit in syrup.
4. Ultra-processed food. These are made with ingredients you wouldn’t use at home (such as chemicals, colourings, sweeteners, and preservatives). Some of the UK’s favourite ultra-processed foods include industrially made bread, ready meals, breakfast cereals, sausages, chicken nuggets, sweets, crisps, soft drinks. Lots of stuff that we all know isn’t great. But it also includes things we might think of as pretty wholesome, like baked beans, tinned soup, meat alternatives, and dairy substitutes such as soya milk.
Do I need to feel guilty about eating anything that isn’t a raw vegetable?
No! The classifications above are important – when we talk about negative health and environmental impacts, we’re almost always talking about ultra-processed foods. And even then, there are important distinctions to be made.
Okay, so what are the environmental impacts of ultra-processed foods?
It varies, but the worst offenders could be linked to any or all of the following:
Industrial farming impacts. Mass-produced foods use mass-produced ingredients. Many staple crops – such as wheat and maize – are grown as intensive monocultures (huge fields of a single crop grown repeatedly), using artificial chemical fertilisers and pesticides. This degrades the soil, damages ecosystems, reduces biodiversity, and contributes to agricultural pollution of land and water.
Greenhouse gas emissions. The world’s food systems generate one third of all greenhouse gas emissions. This is partly because of agriculture – but also because of the carbon impacts of processing, refrigeration, and transportation. Research has shown that ultra-processed foods are linked to more greenhouse gases than other food groups.
Problem ingredients.Ultra-processed foods are more likely to contain known offenders like palm or soy oils, which are renowned for their “substantial negative environmental effects”, including vast tropical deforestation.
More food waste. Longer supply chains result in more going to waste. About half of all food waste happens in the supply chain, between farms and manufacturers, before the finished product even arrives on shop shelves.
Plastic pollution. Ultra-processed foods tend to be heavily packaged, usually in single-use plastic.
Damaging diets. Sugar, salt, and fat can make ultra-processed foods really tempting – but not filling or nourishing. When food is processed, its nutrient availability in your small intestine might be affected, because properties of the plant and animal cells have been altered. Research shows that people tend to overeat these foods – and the more calories you eat, the higher the environmental impact of your diet. Those resources could have been used to produce a more nutritious food, which you would need less of to feel satisfied.
Driving land use change. This desire to eat ultra-processed foods, and eat lots of them, is increasing their global market, and driving more land to be converted to industrial farming.
None of that sounds appetising. So, ultra-processed foods bad, everything else good?
Not quite. Like all sustainability questions, it’s complicated. If you’ve been reading this and mourning certain staples in your kitchen, you’ll be glad to hear that some ultra-processed foods are lower impact than others – and some may even be the more sustainable option.
Ultra-processed foods have a lower impact if they contain no, or very little, animal-derived ingredients. For example, producing a vegan cheese-like spread made from lupin beans uses one fifth of the land needed to make the same amount of cow’s milk cheese, and 1kg of plant-based protein requires 100 times less water than 1kg of animal protein.
Minimally processed vegetarian foods have among the lowest environmental impacts of all. Thanks to the efficiency of scale, a manufacturer could potentially use less energy and produce less waste than you would at home to perform simple processes. Dried fruit, pre-sliced or frozen veg, pre-cooked rice – these may all result in lower emissions than buying the raw ingredients to prep yourself.
However, to make this grey area even more grey: processed foods do still use more plastic packaging, even when they are otherwise sustainable.
That makes sense, just about. So, what should I actually do?
No one expects you to avoid ultra-processed foods altogether; it’s not realistic. Many people are time poor, and ultra processed foods are also often those on offer or discounted – look up the junk food cycle for more on that. But it is worth understanding how to make intelligent compromises.
When you can, try to cook from scratch. Buy your raw ingredients from sustainable sources – organic produce is easy to find on supermarket shelves, or go to a specialist organic shop, such as Riverford, or your local community farm or independent grocer.
And when you need to save a little time, go for minimally processed rather than ultra-processed ingredients, or choose a plant-based option, as part of a scratch-cooked meal.
I’m not convinced yet. Give me one more reason before I go.
Not only will dodging ultra-processed foods be better for the planet – it will be better for you, as psychologist Kimberley Wilson reveals in her new book Unprocessed. The foods associated with the lowest environmental impacts (such as whole grain cereals, fresh fruit and veg, legumes, nuts, and olive oil) are also the healthiest.