Ultra-Processed Foods: Why is what tastes so good so bad for you?

Why is it that documentaries highlighting the awful reality of ultra-processed foods drive you to want to eat more ultra-processed foods? Netflix’s new documentary You Are What You Eat: A Twin Experiment reveals the horrors of industrial farming and then features fried chicken and burgers that look, quite frankly, still utterly delicious. 

I’ve watched the BBC’s Panorama Ultra-Processed Food: A recipe for ill health? twice. One time with my family. We listened to Dr Kesar Sedhra explicitly state: “The chronic disease escalation is primarily related to food intake. There is no question about it”, while we finished-up (read: ‘scoffed’) salt-and-vinegar crisps, chocolate and diet coke. 

That’s how strong our pull to ultra-processed foods is, and we’re not alone in this. In the UK, ultra-processed foods make up 50% of diets for adults and 65% for children, and it’s increasing [1]. 

Professor and ultra-processed foods expert Tim Spector puts it bluntly: 

“That means more type-2 diabetes, more cancers, more heart disease, more misery, more mental illness. This really is a future time bomb… and we’re sleepwalking into it.”

Photo by Kampus Production

What exactly are ultra-processed foods? 

Most foods are at least minimally processed in some way to make them edible or preserve them – pasta, frozen peas, milk, honey, dried fruit. These are not the problem. 

Ultra-processed foods, however, have typically been altered in such a way that we don’t recognise the raw ingredients. They tend to have long ingredient lists that include additives, preservatives and emulsifiers – ingredients that you are unlikely to have in your kitchen cupboards.  

Looking at it another way:

“It is food which dominates the shelves in our supermarkets, dominates much food advertising on television, food which takes up half of the average UK diet with the largest consumption seen in children,” reports Radio 4’s The Food Programme podcast, titled UPF WTF?

Ultra-processed foods include McDonald’s, pizza and fizzy drinks, crisps and chocolate, packaged bread, breakfast cereals, microwave meals, fruity yoghurts… you get the picture. 

Pizza and burgers
Photo by Polina Tankilevitch

Ultra-Processed Foods: why is what tastes so good so bad for you?

The problem with ultra-processed foods is not only that they tend to be higher in fats, salts and sugars. Or that packaging which states ‘high in fibre’, ‘low in sugar’, ‘low in salt’ and ‘plant based’ leads us to believe we’re eating products that are healthier for us than they really are [2].

The issue is also that the processing and the additives all work together to create a product that’s typically high in energy (calories), low in nutritional benefit, and this is impacting our health in ways we are only just starting to understand.

Studies have shown that people who eat a lot of ultra-processed food typically eat up to 500 more calories each day than people who eat more whole-foods [3].    

Have you ever eaten at McDonald’s and felt hungry about an hour later?

Nutritionist Lucy Williamson explains that when we ultra-process food, we change the structure of it and one result of this is that the sugars are much easier for us to absorb. This sugar-hit feeds the reward centre in our brain, so it gives us immediate pleasure. 

It also leads to spikes in blood sugar levels. In response, our bodies produce insulin to regulate this, the drop in blood sugar stimulates our appetite again. Feeling peckish, we reach for more ultra-processed food because we’re looking for a repeat ‘hit’. Hence, its addictive nature. 

If we were eating whole foods or minimally processed foods (see below for examples), our bodies take longer to break down the food. This means we don’t have the highs followed by the lows. 

These sugars are also problematic for our gut health. The gut is important for regulating our immune system and protecting us against certain types of cancer, just two of its many important functions.

“I think it’s one thing in nutrition that we all agree on, ultra-processed foods are bad,” says Williamson. 

Photo by Darya Sannikova

What UPFs to immediately avoid

When it comes to health, the research is clear that there are some things to immediately avoid. 

A good starting point is to avoid the sweetener aspartame. A study at cancer research centre, the Ramazzini Institute, found links between aspartame – a sweetener often used instead of sugar in ultra-processed food and drink – and a number of cancers in different organs, including nervous system tumours, memory cancer, kidney, and leukaemia. [4].

Also, avoid emulsifiers (typically listed as ingredients you don’t recognise i.e. mono and diglycerides, sodium stearoyl lactylate, carrageenan, carboxymethylcellulose and polysorbate-80). 

One of the world’s biggest studies into food additives, NutriNet Sante, which involves more than 174,000 people, also shows a strong correlation between the additives we ingest and the likelihood we are to develop cancer and other diseases [5].

BPA plastic, which many ultra-processed foods are packaged in, should also be avoided.

Photo by Jytte Elfferich

So, what can we eat?

Here’s seven tips Williamson recommends for a healthy diet – what to put on your plate and what to watch out for in the supermarket:

  1. Fill your plate with two-thirds plants. This can include fruit, veg, pulses, grains, peas, beans, nuts and seeds.

  2. Choose ‘nutrient-rich’ foods for the other third – (not industrially farmed) fish, meat, dairy or eggs, for example. Good vegan options include lentils, peas, beans and other pulses, and protein-rich grains and seeds like quinoa and chia.

  3. Swap sliced mass-produced bread for wholesome sourdough. Note: supermarket breads are full of additives, and they don’t have to list all the ingredients they put into the bakery breads that smell so good as you walk into the store.

  4. Watch out for hidden sugar – for example cereal bars, granolas marketed as ‘healthy’ or sauces like ketchup and mayonnaise. Adults should eat no more than 6 teaspoons daily (30g) and children no more than 5 teaspoons (25g).

  5. Check back of pack labelling: do you keep these ingredients in your own kitchen cupboard? If not, they shouldn’t be in your food.

  6. Always choose the most natural option. Opt for whole, plain yoghurt rather than flavoured or whizz up a tomato sauce rather than buying a ready-made alternative.

  7. A word of warning: ‘low fat’ often has other additives to improve the texture; it’s best to opt for the unaltered version. 

If it sounds tough, that’s because it is hard to wean yourself off an addictive diet. But, Williamson maintains the benefits will soon start to outweigh any perceived sacrifice: 

“The amazing thing is, when you eat in this way, you start to feel so much more energised. Everything just starts to work a little bit better, you’re sleeping better, and your emotions are not so up and down –  even if you don’t have any particular health conditions. When you notice the health benefits, you don’t necessarily want to eat the ‘treat’ foods anymore, you don’t want to go back to that.” 


[1]. Swinburn, B.A., et al. (2019), The Global Syndemic of Obesity, Undernutrition, and Climate Change: The Lancet Commission report, The Lancet, Volume 393, Issue 10173, 791–846  and Dr Sarah Berry, Kings College London, Panorama Ultra-Processed Food: A recipe for ill health?  

[2] King’s academics highlight impact of ultra-processed food on health

[3] https://pubmed.ncbi.nlm.nih.gov/31269427/

[4] Panorama, Ultra-Processed Food: A recipe for ill health?  https://www.bbc.co.uk/iplayer/episode/m001mp67/panorama-ultraprocessed-food-a-recipe-for-ill-health 

[5] Panorama, Ultra-Processed Food: A recipe for ill health?  https://www.bbc.co.uk/iplayer/episode/m001mp67/panorama-ultraprocessed-food-a-recipe-for-ill-health 

Main image: Anna Shvets


About the author

Lizzie Rivera

Lizzie Rivera

Lizzie Rivera is the founder and chief purpose officer at Live Frankly. She has been writing for mainstream publications for 10 years, specialising in sustainability and ethics since 2014.


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