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The Shocking Truth About Ultra Processed Foods

A platter of ultra processed foods.

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It’s common knowledge that processed food is potentially harmful to our health. Refined carbohydrates, confectionaries, and ready meals are low in essential nutrients and insoluble fibre but such ‘food products,’ Marion Nestle observes, are ‘laden with sugars, hydrogenated fats, salt and excess calories,’ (What To Eat).

However, there’s a new bully on the block that could be even worse for our health.

Ultra processed foods are as nutrient deficient as their slightly less processed counterparts. Also, they are low in vitamins and insoluble fibre. But where ultra processed foods differ is the degree of chemical additives from which they are comprised.

It’s these chemical additives, Dr Chris van Tulleken argues, that are contributing to the increasing prevalence of many dietary-related diseases. In this article, we will look at the most significant ways that ultra processed food could be undermining our health.

Ultra processed foods and obesity

Emerging research is forging an ever-stronger link between ultra processed food consumption and ill health. Tulleken, whom we briefly met above, has compiled a considerable amount of that research in his admirable book Ultra-Processed People. For 300 jam-packed pages, Tulleken takes ultra processed food to task.

Of the many disturbing ways ultra processed foods (UPF) negatively impact our health, obesity seems to be one of the most prominent.

It’s even been claimed that the emerging obesity epidemic coincides with the dietary transition from traditional whole foods to ones comprised primarily of processed and ultra processed foods.

This contradicts the prevailing assumption of the chief cause of obesity. Most people think that a ‘sedentary lifestyle’ is the driving force behind the ever-expanding global waistline. However, ‘In the case of obesity,’ Tulleken observes, ‘inactivity is not a significant contributor […] the primary cause is ultra-processed food and drink.’

How does ultra processed food make us fat?

It's not quite clear exactly how ultra processed food increases obesity risk. Tulleken suggests that it’s partly due to the well-documented fact that we are getting more of our calories from ultra processed food. However, there are also other less intuitive contributing factors.

For example, ultra processed food has been manufactured for maximum consumption. Portion sizes of many UPF products border on the brink of extreme. (Think of the bucket-sized box of popcorn and gallon of coke that are on offer at the cinema.) But why is it that after troughing your way through that banquet of ultra processed food do you still have room for more?

UPF manufacturers, Tulleken maintains, have ‘exploited’ the ‘body’s ability to link calories with a particular smell or flavour.’ In so doing they have essentially found a way to ‘high jack’ the dopamine reward system, thus increasing the addictiveness of ultra-processed foods. This effect is best encapsulated by one of the most famous food branding slogans in history: Once you pop, you can’t stop!

UPF is soft

Another factor is the distinct absence of ‘bite’ of most ultra processed foods. Under the chapter title UPF is designed to be overconsumed, Tulleken tells us that the ‘destruction of the food matrix by physical, chemical and thermal processing means that UPF is, in general soft,’ (Ultra-Processed People – 271).

He goes on to say that this softness enables ‘you to eat it fast, which means you eat far more calories per minute and don’t feel full until long after you’re finished.’

Related: How to Lose 20lbs of Fat >

Ultra processed foods and the microbiome

The microbiome refers to the 100 trillion individual organisms that inhabit our gut. While we might take pleasure in viewing ourselves as a single species – Homo sapiens – in truth, we are a walking talking symbiotic ecosystem. (Apparently, in one cubic square centimetre of your intestines, there are more microbes than the total number of humans that have ever existed across our 250,000-year history.)

The bacteria in our gut aren’t merely hitching a free ride. As well as suppressing the proliferation of harmful bacteria, they help break down much of the food that we consume. We wouldn’t be able to extract nutrients from food if it wasn’t for the microbiome.

Beyond aiding digestion, emerging research into the microbiome is revealing just how important it is to health.

Gut microbiome and health

Dr Tim Spector, author of The Diet Myth, brings our attention to the recent explosion in obesity rates. ‘In the UK in 198 only 7 per cent of men and women were obese – now [2015] it is 24 per cent.’ (To update that percentage, according to UK government statistics, ‘In 2021 to 2022, 25.9% of adults aged 18 years and over in England were estimated to be living with obesity.'

Spector explores possible reasons that could account for this 17 per cent increase.

He argues that it can’t be a consequence of genetic factors because genes ‘cannot change that fast and traditionally need a minimum of around one hundred generations to adapt by natural selection,’ (The Diet Myth – p12).

Having cleared the crime scene of any genetic foul play, Spector presents a simple suggestion. Perhaps ‘we have been ignoring’ a ‘major factor that influences our diet and health: this is our tiny gut microbes that may hold the answer to our modern obesity epidemic.’

But as he later explains, as well as likely being responsible for the emerging obesity epidemic, the breakdown of the microbiome could be contributing to the increasing rates of diabetes, cancer, and heart disease.

Ultra processed food and the microbiome

Bringing the discussion back to ultra processed foods, Tulleken explains ‘how the preservatives and emulsifiers in UPF disrupt the microbiome, how the gut is further damaged by processing that removes the fibre from food, and how high levels of fat, salt and sugar each cause their own specific harms,’ (Ultra-Processed People – p155).

In addition to disrupting the microbiome, ultra processed foods could also be starving it of essential nutrients.

Tim Spector tells us that ‘It is useful to think of your microbial community as your own garden that you are responsible for’ (The Die Myth – p19). To keep your garden healthy and full of life you need to enrich the soil (your intestines) and grow healthy plants (your microbes).

The surest way to cultivate your microbial garden is to weed out ultra processed foods from your diet while increasing your consumption of whole grains, fruits, and vegetables.

Related: Start living life on the veg with these Plant-Based Recipes >

Ultra processed food and mental health

Ultra processed foods may negatively impact the functioning of the brain. It’s no mystery that food affects our mood. We feel good when we eat a balanced diet because, from a psychological perspective, we know that we are providing our body with the essential nutrients it needs to keep us healthy.

But also, a balanced diet consisting of ‘common foods from leafy green vegetables to your basic garden-variety tomato may positively affect your brain chemistry and help ward off depression,’ (How Not To Die – p200).

In contrast, if you eat a McDonalds meal, you’ll enjoy the dopamine high you get from the sudden deluge of sugar, salt and fat. (And chemicals! According to the YouTube channel Inside Food, the humble Big Mac contains 50 ingredients some of which include xanthan gum, propylene glycol alginate, and polysorbate 80). However, the high is fleeting and is inevitably followed by a crash.

Compounding the frustration of having undermined our health, the drop in dopamine leaves us feeling lethargic and craving more. This can result in mood swings and other mental health problems.

Ultra processed food and the brain

It transpires that young people are particularly at risk here, and not simply for the fact that they form one of the largest ultra processed food consumer demographics. Questions have been asked about the possible ways that chemically adulterated food could harm developing brains.

During a discussion with a professor of magnetic resonance physics, Tulleken raised the concern that, like addictive drugs, ultra processed foods could be ‘messing around with the [dopamine] reward pathway’ and thus paving the way to early dependence.

Moreover, other unnerving questions were raised such as ‘Will UPF affect their IQ, their social performance?’ Ultimately, the disconcerting answer is, ‘We just don’t know what’s happening to children’s brains [when consuming these types of foods].’

UPF and hormone regulation

The link between ultra processed food consumption and impaired cognition is still being investigated. However, what studies have shown is that UPF can derange hormone regulation.

After consuming only ultra processed foods for a month, an experiment he conducted while writing his book, Tulleken revisited researchers for testing at the end of his diet. The outcomes both shocked and disturbed him.

In addition to gaining 6kg of fat, his ‘appetite hormones were totally deranged.’ Moreover, the 'hormone that signals fullness barely responded to a large meal, while the hunger hormone was sky high just moments after eating.’

Other adverse effects included a ‘five-fold increase in leptin, the hormone that comes from fat,’ and a two-fold increase in C-reactive protein levels, ‘a marker that indicates inflammation.’

Ultra processed food linked to early death

In addition to exacerbating obesity, sending our microbiome out of whack, and discombobulating chemical hormone regulation, Tulleken identifies a long list of other ‘non-communicable’ diseases linked to the consumption of ultra processed foods.

A non-communicable disease (or NCDs), by the way, ‘tend to be of long duration and are the result of a combination of genetic, physiological, environmental and behavioural factors.’ The main types of NCD include cardiovascular disease (heart attacks and strokes), cancers, chronic respiratory disease, and diabetes. Globally NCDs account for a staggering 31.4 million deaths annually (WHO).

Though I have no insights to support the following assumption, it seems to me that the prevailing public opinion holds that NCDs are the result of forces beyond our immediate control. I’ve heard it said that cardiovascular disease is something that comes with age. And that nearly all cancers are a consequence of genetics.

Yet, in the opening pages of How Not To Die, Dr Greger maintains that 90 per cent of NCDs are caused by a single factor. That factor is diet – more specifically, the ‘Standard Western Diet’ (SAD) which is characterised as being high in animal protein and processed and ultra processed foods.

Related: Transform your diet with these Easy Vegetarian Meals >

UPF and cancer

Emerging research is continually strengthening Greger’s claim. Just recently a team of esteemed scientists published a paper entitled Is early-onset cancer an emerging global epidemic?.

The authors of the paper conclude that the ‘incidence of cancers of various organs diagnosed in adults ≤50 years of age has been rising’ for the past three decades. They go on to say that the early-onset cancer epidemic might be the early life exposure to, among other things, poor dietary practices (Ugai, T., Sasamoto, N., Lee, HY. et al.).

Further supporting Dr Greger’s claim, a 2023 paper published in the prestigious Lancet outlines the health risks of a diet high in ultra processed foods. The findings of the study showed that ‘every 10 percentage points increment in UPF consumption was associated with an increased incidence of overall […] and specifically ovarian […] cancer.’ Furthermore, the dietary percentage of UPF was also associated with an ‘increased risk of overall […], ovarian […], and breast […] cancer-related mortality.’ (Read the full article here: Ultra-processed food consumption, cancer risk and cancer mortality >)

Ultra-processed foods and NCD

On introducing the list of diseases linked to a diet high in ultra processed foods, Tulleken observes that ‘most studies focus on obesity, but there is also evidence that increased UPF intake is strongly associated with an increased risk of’ many ‘non-communicable diseases’ (NCD).

The NCDs listed by Tulleken include:

  • ‘death – so called all-cause mortality

  • cardiovascular disease (strokes and heart attacks)

  • cancers (all cancers overall, as well as breast cancer specifically)

  • type 2 diabetes

  • high blood pressure

  • fatty liver disease

  • inflammatory bowel disease (ulcerative colitis and Crohn’s disease)

  • depression

  • worse blood fat profile

  • frailty (as measured by grip strength)

  • irritable bowel syndrome and dyspepsia (indigestion)

  • dementia’


To conclude

In this article, we have reviewed the various ways that the consumption of ultra processed foods can deteriorate our health. Much of the discussion leans heavily on Dr Chris van Tulleken’s brilliant book Ultra-Processed People.

Conscious of keeping the content concise, I have omitted lots of fascinating (more accurately, disturbing) insights. For example, Tulleken exposes the environmental impacts of UPF. He quite admirably dedicates many pages to the environmental destruction of the UPF manufacturing process and how it contributes disproportionately to climate change while degrading agricultural land and exacerbating plastic pollution.

Furthermore, Tulleken also raises awareness of corporate corruption that seeks to obfuscate the impacts of UPF on health while undermining the democratic process. For instance, big businesses use their financial and legal might to bulldoze any social or governmental initiatives that aim to tighten the regulation of the sales of UPF products.

Considering the many limitations of this article, I urge you to get a copy of Ultra-Processed People. That way you will gain a science-backed insight into the myriad ways UPF adversely impacts our health. Also, you will learn how to remove ultra processed foods from your diet for good.


About Adam Priest –

A former Royal Marines Commando, Adam Priest is a content writer, college lecturer, and health and wellbeing practitioner. He is also a fitness author and contributor to other websites. Connect with Adam at



Greger, M. Stone, G (2017) How Not to Die. USA. Macmillan.

Spector, T. (2015) The Diet Myth. London. W&N publication.

Tulleken, C (2023) Ultra-Processed People. Cornerstone Press. UK.

(Ugai, T., Sasamoto, N., Lee, HY. et al. Is early-onset cancer an emerging global epidemic? Current evidence and future implications. Nat Rev Clin Oncol 19, 656–673 (2022).)

UK government statistics on obesity, ‘In 2021 to 2022, 25.9% of adults aged 18 years and over in England were estimated to be living with obesity.'

World Health Organisation (WHO – 2023) Noncommunicable Disease Key Facts. According to the WHO, NCDs are responsible for:

  • 41 million pre-mature deaths annually (74% of all deaths globally)

  • 17 million early life deaths (under the age of 70)

  • A massive and disproportionate cause of the total global disease burden (including cardiovascular disease, cancers, chronic respiratory disease, and diabetes)

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