On this page:
- What are processed foods?
- Why are foods processed?
- What are ultra-processed foods?
- Can food processing affect health?
- How do processed and ultra-processed foods affect your risk of developing diabetes?
- Healthy swaps and tips
What are processed foods?
The term processed food does not have a consistent definition and it could refer to any food that has undertaken any process, such as chopping, freezing, canning or cooking.
However, more generally, processed foods refer to foods which have had other foods or ingredients added to them.
Why are foods processed?
Food processing has a number of roles including:
- Making sure foods are safe to eat by killing harmful bacteria that can cause food poisoning (for example, pasteurising milk and cooking raw meat, fish and eggs).
- Helping food last longer (for example, freezing fruit and vegetables helps them stay fresh for longer while keeping most of their vitamins and minerals, and adding salt or preservatives to meats like salami and bacon helps stop them from spoiling).
- Changing or improving the nutrients in food products (for example, reducing saturated fat, free sugar or salt, or adding calcium to some plant-based milks to help make them more similar to dairy milk).
- Making food more enjoyable to eat by improving taste, texture and smell (for example, baking bread).
- Making food quicker and easier to use (for example, using tinned beans when preparing meals).
What are ultra-processed foods?
In the UK, there is no universally agreed definition for ‘ultra-processed foods’ (UPF). The term comes from the NOVA food classification system, which was developed by researchers at the University of São Paulo, Brazil.
They developed a system that places food into four categories based on the amount of processing, starting from unprocessed or minimally processed foods, to processed ingredients and foods, and then ultra-processed foods.
- Unprocessed or minimally processed foods like fruit, vegetables, fresh and pasteurised milk, plain yoghurt, eggs, fish, seafood, beans, lentils, whole grains (e.g. oats), rice (white, brown or parboiled), plain nuts and seeds.
- Processed culinary ingredients like salt, sugar, olive oil, and butter.
- Processed foods, such as cheese, fresh bread, salted nuts, canned fish, smoked or salted meats and canned vegetables.
- Ultra-processed foods, like fizzy drinks, sliced packaged bread, fruit yoghurt, sweetened milk drinks, sausages, hot dogs, chicken nuggets, ready meals, sweets, chocolates, crisps, alcohol (such as spirits), cereal and energy bars.
In this information, we use the term “ultra-processed foods” to describe foods classified as UPF using the NOVA system. However, simply labelling a food as ultra-processed does not tell you how healthy it is. Classifying foods in this way looks mainly at how a food is made, not its overall health properties, so it does not always help you understand whether a food can fit into a healthy, balanced diet.
Ultra-processed foods are products classified as industrially made and contain one or more ingredients that you maybe wouldn’t normally find in a kitchen, such as artificial flavours, colours, artificial sweeteners, or emulsifiers. These foods are convenient and ready-to-eat or drink and are heavily packaged and marketed.
Can food processing affect health?
Observational studies suggest there is an association between higher consumption of foods classified as ultra-processed and health conditions such as: type 2 diabetes, gestational diabetes, overweight and obesity, high blood pressure, cardiovascular disease, and depression.
There are also other risk factors for these health conditions such as age, ethnicity, and genetics. UPF as a terminology and its effect on health is still emerging.
Not all experts agree with the NOVA system because it groups foods based on how they are processed rather than how nutritious they are. This means very different foods can be classified as UPF in the same category.
For example, white bread and wholegrain sliced bread are both categorised as UPF, but they do not have the same health properties. Wholegrain bread has more fibre, which is associated with a lower risk of type 2 diabetes and other conditions, whereas white bread has less fibre.
Because of this, it is important not to assume that all foods classified as UPF are unhealthy.
Some processed and ultra processed foods can support a healthy, balanced diet because of the nutrients they contain. For example, reduced sugar and salt baked beans are classified as ultra-processed, but they are low in fat and a source of fibre and protein. Half a large tin of baked beans also counts towards your five-a-day.
Similarly, artificial sweeteners, such as aspartame and sucralose, are ingredients that can be found in some diet or 'no added sugar' fizzy drinks which some people can find helpful if they are trying to reduce their sugar intake.
It's important to focus on foods and their nutritional benefit and how they fit into your overall diet, rather than relying on whether they are classified as UPF or not.
However, some processed foods, such as processed meat, have been linked to cancer, particularly bowel cancer. Read more on red and processed meat.
How do processed and ultra-processed foods affect your risk of developing diabetes?
Many foods classified as UPFs are designed to taste very appealing, which can make it easy to eat more than we need.
In the UK, more than half of the energy (calories) an average person eats and drinks comes from foods that would be classified as ultra-processed (UPF).
As many of the foods classified as ultra-processed are typically high in calories, free sugars, fat, salt and processed meat, having too much of these is not good for long-term health, so people with and without diabetes are advised to reduce their intake.
It is not known if ultra-processed food alone is associated with an increased risk of type 2 diabetes, as there are many factors such as activity levels, sleep and dietary patterns, among other things, that can affect a person’s risk of type 2 diabetes.
So, it is important to follow a healthy diet, reduce alcohol, do more physical activity and get support to stop smoking if you smoke.
Diets high in foods classified as ultra-processed are also typically low in fruit and vegetables and fibre. Eating more fruits and vegetables and including some wholegrain products and fermented dairy, like yoghurt and cheese lowers your risk of type 2 diabetes as these foods are protective for health.
You can find out more about how to reduce your risk of type 2 diabetes.
Healthy swaps
It is difficult to avoid processed foods altogether which is why it is important to try to choose a healthier option as much as possible. For example:
- Swap original baked beans to reduced salt and sugar baked beans
- Swap sweetened flavoured yoghurts to plain natural yoghurt, Greek yoghurt, or fromage frais topped with chopped fruit
- Swap fried French fries to homemade potato chips cooked in an air fryer
- Swap white bread for whole grain bread
- Swap smoothie pouches to fruit such as a chopped or mashed banana
- Swap chocolate cereal to low-sugar wholegrain breakfast cereals
- Swap processed cheese slices to cheddar cheese.
Diets based around nutrient-rich foods such as wholegrains, fruit and vegetables, pulses, fish, nuts, seeds and unsweetened dairy foods are better for our long-term health.
It's important to eat less red and processed meat like bacon, ham and sausages and reduce sugar sweetened foods and drinks, choosing water instead or other unsweetened drinks including tea and coffee.
Here are some other helpful healthy tips:
- Try make time over the week for food prep and healthy home cooking. Add vegetables and beans to meals to pump up the fibre and protein content and make the meal go further. For example, replace some of the mince meat in a chilli con carne with a can of drained kidney beans in water. Or, add a tin of chopped tomatoes to ready-made pasta sauces and look out for sauces with no added sugar and salt.
- Bulk cook at home if you can and freeze the extra portions for another day instead of picking up a ready meal which can be high in sugar, fat and salt.
- Check food labels on pre-made food products and drinks for hidden sugars, fat, and salt. Usually, the longer the ingredients list, the more likely a product is to be ultra-processed. Read more here on understanding food labels.
- Pack healthy snacks like fruit and vegetables, or some unsalted nuts to take with you instead of picking up a snack from a convenience store.
