Chapitre 1
The Hidden War in Your Kitchen: How Ultra-Processed Foods Hijack Your Body
In a world where nearly 60% of what we eat isn't actually food but "edible substances," Chris van Tulleken's "Ultraprocessed People" arrives as a wake-up call that's both terrifying and liberating. This book has become a cultural phenomenon, spending weeks atop bestseller lists and sparking global conversations about what we're really putting in our bodies. Celebrities from Gwyneth Paltrow to Jamie Oliver have championed its message, while food industry giants have scrambled to counter its claims. Van Tulleken, a physician and BBC presenter with a background in infectious disease, approaches our modern food crisis through the lens of evolutionary biology-revealing how the food industry has weaponized our own biological drives against us in what may be the most consequential arms race in human history.
Chapitre 2
The Evolutionary Arms Race on Your Plate
Our bodies are battlegrounds in an ancient evolutionary conflict. Just as viruses and cells engage in endless evolutionary combat-developing weapons and defenses in perpetual cycles-humans have been locked in a biological arms race around food since our earliest days. For millions of years, this competition shaped every aspect of our physiology, from our intricate digestive systems to our complex brain chemistry, creating sophisticated mechanisms to regulate what, when, and how much we eat. These mechanisms include hormones like leptin and ghrelin, neural pathways that process reward and satisfaction, and metabolic systems that convert food into energy.
But something unprecedented and deeply concerning happened in the last 150 years. Our food transformed into something fundamentally unrecognizable-substances constructed from novel molecules and industrial processes never encountered in our evolutionary history. These ultra-processed foods (UPFs) now constitute up to 60% of diets in countries like the UK and USA, with even higher percentages among children and lower-income populations, creating an entirely new ecosystem where humans have become prey in a corporate competition for profit.
The formal definition of UPF comes from the NOVA classification system developed by Brazilian scientist Carlos Monteiro in 2010. While technically complex, the practical definition is simpler: if it's wrapped in plastic with ingredients not found in a standard kitchen, it's probably UPF. This includes obvious "junk food" like chips and sodas, but also many supposedly "healthy" products with nutrition claims-protein bars, vitamin-fortified cereals, meal replacement shakes, and even many plant-based alternatives. A typical UPF might contain dozens of ingredients, including industrial substances like modified starches, hydrogenated oils, protein isolates, and various emulsifiers and stabilizers.
What makes UPF particularly dangerous is that it's designed-through a process of corporate natural selection-to subvert our body's regulatory systems. Products that cause people to consume more are more profitable and thus proliferate in the marketplace. Food scientists carefully engineer these products to hit the "bliss point" of maximum palatability, combining precise ratios of salt, sugar, and fat with texture-modifying additives. They create hyperpalatable foods that override our natural satiety signals, leading to what researchers call "passive overconsumption."
The evidence linking UPF to health problems is overwhelming and growing rapidly. Large-scale epidemiological studies show UPF consumption directly damages human health, increasing rates of various cancers by up to 30%, metabolic disorders like type 2 diabetes, and mental health conditions including depression and anxiety. It destroys traditional food cultures, drives health inequality between socioeconomic groups, and severely harms the planet. Industrial food production is causing a synergistic pandemic of climate change, malnutrition, and obesity-becoming the leading cause of declining biodiversity and the second-largest contributor to global emissions after fossil fuels.
Most disturbingly, the risks increase with consumption regardless of weight gain, affecting conditions from dementia to inflammatory bowel disease. Recent research suggests UPFs may alter our gut microbiome, disrupt hormone function, and trigger systemic inflammation. We're not just becoming heavier; we're becoming fundamentally different beings-ultraprocessed people, our bodies and minds transformed by industrial food technology in ways we're only beginning to understand.
Chapitre 3
The Birth of Food That Isn't Food
The story of ultra-processed food begins with a simple human desire: to create cheaper alternatives to expensive natural products. In 1869, Napoleon III offered a prize for creating an affordable butter substitute to feed both his armies and the poor. The winner, chemist Hippolyte Mege-Mouries, created the first margarine through what may be considered the first ultra-processing technique-a complex method involving rendered beef suet, stomach enzymes, bleaching agents, and colorants. This innovation marked the beginning of food engineering that would transform global eating habits.
The true breakthrough came with hydrogenation at the turn of the 20th century, allowing plant oils to be solidified through chemical processing. This discovery revolutionized food manufacturing by creating shelf-stable fats that could withstand long periods without refrigeration. Procter & Gamble developed Crisco from cottonseed oil in 1907, creating possibly the first mass-produced UPF. The oil, previously considered industrial waste, required extensive processing including detoxification and "RBD" processing-refining, bleaching, and deodorizing-to remove gossypol toxin and unpleasant flavors. P&G marketed Crisco as more "pure" and "digestible" than animal fats, despite having no historical precedent in human nutrition.
Today, this RBD process creates the bland, interchangeable oils (soybean, palm, canola, sunflower) that comprise 90% of the global market. These oils undergo extreme processing at temperatures exceeding 500F, using chemical solvents like hexane for extraction. UPF manufacturers list multiple fats on packaging so they can use whichever is cheapest without changing labels - a practice known as "multiple naming." These processed fats-which humans never previously consumed in history-are now the fundamental building blocks of ultra-processed foods.
The contrast with traditional foods is stark. Take butter, for example. Unlike modern substitutes, butter is an "inverted emulsion" that naturally preserves fat-soluble vitamins (A, D, E, and K) and essential fatty acids without refrigeration. Evidence of butter production dates back 8,000 years to the Sahara Desert, where rock art shows cattle being milked and pottery shards contain milk residue processed into cheese or butter-like products. Though early humans lacked the enzyme lactase to digest milk sugar, they developed sophisticated preservation techniques like yogurt and butter that remained central to food cultures worldwide. These traditional methods relied on fermentation, churning, and other natural processes that enhanced both preservation and nutrition.
The most disturbing chapter in UPF history may be "coal butter"-the first truly synthetic food-developed in Nazi Germany by chemist Arthur Imhausen. This "Speisefett" was manufactured by synthesizing fats from coal through complex chemical processes. It was tested on over 6,000 concentration camp prisoners despite animal studies showing it caused severe kidney problems and bone decalcification. After the war, the Allies discovered Imhausen's synthetic butter plant with machinery stopped mid-production and enormous cylinders of synthetic fat-a chilling reminder of how industrial food production can prioritize efficiency over humanity. This dark episode exemplifies the extreme lengths taken to create artificial alternatives to natural foods, often with devastating human consequences.
Chapitre 4
The Scientific Case Against UPF
The evidence supporting Ultra-Processed Foods (UPF) as a primary cause of global health problems has grown from a trickle to a deluge since Kevin Hall's groundbreaking 2019 study at the National Institutes of Health. Critics initially argued that UPF is simply nutrient-poor food high in fat, salt, and sugar; that it displaces healthier foods from the diet; or that UPF consumption merely indicates poverty or generally unhealthy lifestyles. However, researchers have meticulously controlled for these factors in multiple studies across different populations and cultures, and the harmful effects of UPF consistently persist independently.
The evidence has become overwhelming: increased UPF consumption strongly correlates with numerous serious health conditions. Large-scale studies show higher all-cause mortality rates (26-62% increased risk across various populations), with particularly strong associations for cardiovascular disease and cancer. The risk of type 2 diabetes increases by up to 40% with high UPF consumption, while conditions like high blood pressure, fatty liver disease, and inflammatory bowel disease show similar correlations. Mental health is also affected, with significant links to depression and anxiety. Perhaps most concerning is the connection to dementia, where research indicates that just a 10% increase in UPF intake associates with a 25% higher risk of cognitive decline and dementia.
Most alarming is that current nutritional guidelines fundamentally fail to account for food processing levels. A person could strictly follow official dietary guidance, consuming foods low in fat, salt, and sugar, yet still consume harmful levels of UPF. This blind spot in nutrition policy is exemplified by Europe's Nutri-Score system, where even foods rated as "high-quality" include up to 25% UPFs. The system's focus on traditional nutrients while ignoring processing status represents a critical oversight in public health policy.
The food industry's involvement in challenging UPF research follows a familiar pattern seen previously with tobacco and sugar research. Papers critical of the NOVA classification system (which categorizes foods by processing level) frequently have authors with undisclosed conflicts of interest. A notable example is Julie Miller Jones, whose widely-cited work questioning UPF research was actually ghostwritten by an industry task force representing major UPF manufacturers. Analysis of industry-funded studies consistently shows results biased in favor of industry interests, with such studies being 88% more likely to find favorable outcomes compared to independent research.
Three robust pillars of evidence now firmly link UPF to poor health outcomes: First, fundamental biological evidence demonstrates how specific UPF characteristics (including ingredient combinations, processing methods, and physical properties like softness and energy density) directly impact human metabolism and gut health. Second, Kevin Hall's small but rigorously controlled clinical study showed that UPF diets lead to increased calorie intake and weight gain even when matched for nutrients. Finally, dozens of independent epidemiological studies, involving hundreds of thousands of participants across multiple continents, show convincing links between UPF consumption and various health conditions, including premature death.
Chapitre 5
Beyond Willpower: How UPF Hijacks Your Body's Controls
The pervasive belief that willpower can override our internal food regulation system is deeply flawed. This idea creates stigma specifically around weight gain, unlike other diet-related diseases. While obesity has genetic components-both rare single-gene defects and more common minor genetic differences affecting eating behavior-the environment plays the decisive role.
Our bodies have sophisticated internal systems that precisely regulate food intake, simultaneously solving two critical problems: consuming the right amount of essential micronutrients while maintaining proper energy balance. The energy regulation system-controlling body fat-involves complex hormonal signals including leptin, a hormone produced by fat tissue that communicates with the brain about body fat stores.
Fat isn't merely inert storage but a sophisticated endocrine organ producing hormones that regulate weight. Both long-term systems (like leptin) and short-term systems (involving signals from the liver, pancreas, stomach, intestines, and microbiome) constantly communicate about what, when, and how much to eat.
Kevin Hall now believes UPF doesn't simply override our fullness signals through deliciousness, but actually "resets the thermostat, bypasses it, or perhaps just breaks it completely." The energy balance model connects hedonic brain areas with nutrient-detection systems, explaining why many people can't stop eating despite feeling physically full. External cues like advertisements and packaging further influence these processes below conscious awareness, making simple advice like "eat less, move more" ineffective-comparable to telling a thirsty person to drink less water.
Food swamps-environments where fresh food may be available but is submerged in a sea of fast-food outlets selling UPF-are particularly problematic. In deprived areas, these outlets can be twice as dense as in affluent neighborhoods. Only UPF is advertised to young people because its proprietary nature generates substantial profit margins. Unlike basic foods like beef or milk, UPF like KitKats have unique "barcodes" that keep consumers returning.
Stress, particularly chronic stress from poverty, increases cortisol secretion, driving increased intake of calorie-dense UPF and potentially leading to visceral fat accumulation. Twin studies have revealed that body-fat percentage is highly heritable-up to 90 percent in some populations. Clare Llewellyn's research with 925 twin pairs demonstrated that heritability depends on food environment. In secure, high-income households, weight heritability was around 40 percent, but in households with lowest incomes and highest food insecurity, it jumped to over 80 percent.
Chapitre 6
The UPF Experiment: What Happens When You Go All In
To understand UPF's effects firsthand, van Tulleken conducted a radical experiment: eating an 80% ultra-processed food diet for four weeks, mirroring the consumption patterns of many Western populations. The results were more alarming than anticipated. After just four weeks, he gained 6kg (13.2 pounds), his appetite hormones - particularly ghrelin and leptin - were completely deranged, inflammation markers doubled, and brain scans showed significant changes in connectivity between regions controlling food intake, desire, and reward. These changes were particularly pronounced in the amygdala and prefrontal cortex, areas crucial for decision-making and emotional regulation.
During the experiment, he experienced intensely disturbing anxiety dreams, including recurring nightmares about food. Physical symptoms manifested quickly: severe constipation leading to hemorrhoids and an anal fissure, disrupted circadian rhythms, and irregular sleep patterns that created a vicious cycle of physical and mental effects. He felt aged ten years - experiencing joint pain, constant fatigue, mood swings, and a persistent brain fog that affected his work performance. His energy levels crashed dramatically, requiring afternoon naps just to function.
When the diet ended, he quit UPF completely, cold turkey. The transformation was remarkable - within 48 hours, his sleep patterns normalized, bowel function returned to regular, and mental clarity improved significantly. Most surprisingly, foods he'd previously binged on compulsively - like certain brands of cookies and chips that he'd consume until physically ill - became completely unappetizing. While "food addiction" remains scientifically controversial, his experience paralleled substance dependency more than behavioral addiction. The compelling urge to consume certain UPFs that specifically target ancient reward centers in the brain was unlike anything he'd experienced before.
Dr. Nicole Avena from Mount Sinai School of Medicine explained the neuroscience behind these effects. These foods activate brain reward systems similar to drugs like alcohol or morphine, particularly affecting dopamine pathways. Brain scans show hyperpalatable foods stimulate the same neural circuits affected by addictive substances, especially in the nucleus accumbens and ventral tegmental area. More disturbingly, she revealed that without the complex matrix of additives, flavor enhancers, and texturizers, the base industrial ingredients would be unrecognizable as food - "almost like eating dirt." This explains why manufacturers invest heavily in "food design" to create irresistible combinations of salt, sugar, and fat.
Fernanda Rauber's observation that most UPF is "not food" but "an industrially produced edible substance" became starkly evident as van Tulleken examined popular products. Grenade Carb Killa bars, marketed as healthy protein snacks, were essentially constructed from modified carbohydrates, isolated proteins, and palm fat. Turkey Twizzlers, once a staple in British school lunches, contained only 63% turkey meat but required 37 different ingredients to create their signature taste and texture. These weren't simply processed foods - they were completely reconstructed substances, assembled from molecular components and made palatable through sophisticated flavor chemistry and textural engineering.
Chapitre 7
The Hidden Dangers of Food Additives
Food additives, once dismissed as harmless, may be more concerning than previously thought. A 2007 study in The Lancet showed that six food colorants and a preservative increased hyperactivity in children, leading to warning labels in the UK. With over 2,000 permitted additives in the EU and possibly 10,000+ in the US, these chemicals are ubiquitous in UPF.
Emulsifiers, which allow fat and water to mix, are particularly common. While some emulsifiers like egg yolk are natural, many like DATEM (diacetyl tartaric acid esters of mono- and diglycerides) are synthetic and may insert themselves into cell membranes, potentially damaging the gut. DATEM gives commercial bread its springy texture and extended shelf life, though its exact mechanisms aren't fully understood.
Research shows emulsifiers like carboxymethylcellulose and polysorbate 80 (found in everything from ice cream to deodorant) damage the gut microbiome. In mice studies, these additives destroyed the protective mucus barrier, allowed bacteria to contact gut cells directly, reduced beneficial bacteria, and caused inflammation that spread throughout the body. This led to increased food consumption, weight gain, and diabetes-like symptoms.
Maltodextrins, another common UPF additive, can cause cellular stress, intestinal inflammation, and reduced immune response. They may encourage harmful bacteria like Salmonella and E. coli to form biofilms and penetrate the body's protective mucus barriers, potentially triggering inflammatory bowel diseases in genetically susceptible individuals.
Other concerning additives include xanthan gum, a bacterial slime that thickens products from toothpaste to drilling mud. Research shows it feeds novel bacterial species that have colonized billions of human guts but are absent in hunter-gatherers who don't consume it. These bacteria may affect immune system development, especially in infants.
The regulation of food additives reveals troubling gaps in consumer protection. While medical drugs undergo rigorous testing costing hundreds of millions of dollars, food additives follow a far more lenient path. The FDA's food additive regulatory system allows companies to bypass thorough safety testing through a loophole called "generally recognized as safe" (GRAS). Originally intended for common ingredients like salt and vinegar, this designation quickly became a way for companies to avoid FDA scrutiny altogether.
Since 2000, only 10 of 766 new food chemicals went through full FDA approval-the other 98.7% were self-determined by the companies making them. Most of these determinations lack data on cumulative effects, developmental impacts, or reproductive toxicity. The burden of proof has shifted from companies to prove safety to civil society groups to prove harm-a nearly impossible task when effects may be subtle, cumulative, and manifest over decades.
Chapitre 8
The Global Impact: From Rainforests to Waistlines
The environmental and social impacts of UPF extend far beyond individual health. Ultra-processed foods destroy traditional diets through corporate strategies like Nestle's in Brazil, where the company uses "direct sales" with door-to-door salespeople bringing UPF into slums, and even created a floating supermarket to reach remote Amazon communities.
The argument for palm oil's necessity is misguided-alternatives like sunflowers can be grown in temperate climates with less carbon impact than clearing carbon-rich tropical forests. Industry claims about "sustainable palm oil" are misleading since the designation lacks formal meaning and independent oversight.
The current food system is fundamentally inefficient in two ways. First, as Wageningen University researchers note, our food contains less energy than it takes to produce it-an illusion of efficiency made possible only by cheap fossil fuels that we collectively subsidize through $6 trillion in externalized costs. Second, plants produce abundant protein that we largely feed to animals rather than eating directly.
The carbon footprint differences are stark: 100g of beef protein produces 25kg of carbon dioxide, chicken 4-5kg, tofu 1.6kg, beans 0.65kg, and peas just 0.36kg. Some nuts are even carbon-negative. While sustainable animal farming exists, it likely can't match our growing meat appetite without further deforestation.
Most meat consumption now comes through UPF (7% of UK diet versus 5% from minimally processed meat). UPF's nature discourages environmental concern and animal welfare standards. Take soy-traditionally not widely eaten because it tastes poor and is hard to digest, it's now heavily processed using fossil fuels to feed animals. About 75% of soy becomes animal feed while the oil enters UPF products.
The UK imports 3 million tonnes of soy annually, mostly causing environmental destruction. Each UK resident effectively uses a tennis court-sized plot of tropical land for their soy consumption, mostly through animal products. With global meat production set to double in 30 years, we'll need Europe-sized areas for feed crops.
This system creates a devastating cycle: deforestation for soy disrupts "flying rivers" of rainfall, creating drought in the very areas growing soy. The southeastern Amazon now produces more carbon than it stores.
Chapitre 9
Breaking Free: Solutions for Individuals and Society
If you want to quit UPF, try what van Tulleken and his twin brother Xand did: go on an 80 percent UPF diet for a few days. You'll quickly understand what researchers mean about "fantasy foods" and "industrially produced edible substances." If you suspect addiction, take the Yale Food Addiction Scale test and seek help from friends, family, or your doctor.
Some people can moderate their UPF intake by identifying trigger products and vulnerable moments, while others find complete abstinence more effective. When you stop eating UPF, you'll need alternatives that cost more time and money-cookbooks by Allegra McEvedy and Jack Monroe offer cheap, easy recipes. Don't expect dramatic weight loss; finding balance might require moderating intake of other foods too.
On a societal level, the evidence points to the need for regulation. Following the money through the food industry reveals a system where everyone is incentivized to maximize sales volume. From farmers receiving just 27% of consumer expenditure, to sales representatives with volume-based bonuses, to food scientists perfecting products through expert tasting panels, to investment bankers facilitating corporate growth-the entire chain prioritizes selling more units to more people more often.
Companies face relentless pressure from financial markets to deliver growth, margins, and dividends. Industry insiders unanimously agree that meaningful change cannot come from within-regulation must come from government intervention. As one unnamed consultant bluntly confirmed, if a company discovers a formulation that makes people eat 5% more, that's exactly what they'll choose.
Alternatives exist-agroecological farming of diverse whole foods could produce enough healthy food on less land with climate benefits. This would make whole foods more abundant while increasing UPF costs, but would avoid the existential threats of climate change and antibiotic resistance that our current system creates.
The science behind UPF's harmful effects is comprehensive: its destruction of the food matrix creates soft products eaten rapidly without triggering fullness; its high calorie density delivers more calories per bite; it displaces nutritious whole foods from diets; the mismatch between taste signals and actual nutrition alters metabolism and appetite; its additive qualities trigger binges; its additives damage the gut microbiome; its convenience encourages constant, thoughtless eating; and its production methods require subsidies while causing environmental destruction.
We're not just what we eat-we've become ultraprocessed people in an ultraprocessed world. But by understanding the forces shaping our food environment and making conscious choices about what we consume, we can begin to reclaim our health, our planet, and our humanity.
