UPFs are defined as anything that contains additives not found in the home and is made to an industrial formulation. These types of foods, such as processed red meats, fizzy drinks, mass-produced bread, crisps, and sweets, now make up over half of the average Brit\u2019s diet, and up to two-thirds in adolescents.<\/p>\n
The lung cancer study found the risk rose after just 12 years of studying the participants. UPFs have also been linked with heart disease, diabetes and other cancers. But when do the risks kick in? Does an occasional pack of biscuits counteract a veg-based diet, or does it take years of heavy UPF intake<\/a> to impact your health?<\/p>\n \u2018It\u2019s important to take a balanced and informed view of UPFs,\u2019 says Rhiannon Lambert, a nutritionist and author of Unprocessed Plate<\/a>. She shares what happens to your body after eating UPFs for days, weeks, months, years and decades.<\/p>\n After a day \u2013 irritability, glucose spikes and cravings for more\u00a0<\/p>\n Eating UPFs for just one day is unlikely to cause long-term harm, particularly within the context of an otherwise balanced diet. \u201cWhile high consumption of UPFs<\/a> can be linked to poorer health outcomes, occasional intake within a nutrient-dense diet is unlikely to pose significant harm. Rather than approaching this with fear, the more constructive response is to build awareness and gradually shift towards more whole and minimally processed foods wherever possible,\u201d explains Lambert. \u201cHowever, even short-term consumption may lead to noticeable effects on how the body feels and functions.\u201d<\/p>\n UPFs tend to be high in refined carbohydrates and added sugars, while typically lacking fibre and essential micronutrients. As a result, they can cause rapid increases in blood glucose, followed by declines, which may contribute to temporary fatigue<\/a>, irritability, and heightened food cravings, Lambert explains. <\/p>\n They\u2019re also known to be high in fat, with one small Journal of Nutrition study<\/a> finding a single high-fat meal increased blood pressure more than a low-fat meal.<\/p>\n But one of the clearest effects people experience when eating a UPF is their addictiveness. \u201cThese foods are engineered to be highly palatable and easy to consume in large quantities. Their soft textures and low fibre content reduce chewing time and slow satiety signals, which may lead to overeating and fullness or gastrointestinal discomfort,\u201d says Lambert. <\/p>\n A 2023 study, published in the British Medical Journal, said UPFs including chocolate bars should be labelled and taxed as addictive substances, as they evoked \u201csimilar levels of dopamine in the brain to those seen with nicotine and alcohol.\u201d The researchers also said people can get addicted to specific flavours and sweeteners added to UPFs<\/a>. <\/p>\n If you typically eat your greens and grains, occasionally overeating a delicious brownie shouldn\u2019t be a concern. \u201cBut these patterns can become more significant when repeated regularly,\u201d adds Lambert.<\/p>\n After one month \u2013 weight gain and worsening gut health\u00a0<\/p>\n The presenter and infectious diseases doctor Chris van Tulleken studied himself eating only UPFs for 30 days, reporting feeling as though he\u2019d aged 10 years in just a month. His symptoms included poor sleep, heartburn, unhappy feelings, anxiety, sluggishness, and a low libido \u2013 and he gained almost 7kg (more than a stone).<\/p>\n In another, groundbreaking trial into UPFs<\/a> at the US National Institutes of Health, 10 men and 10 women were fed either a high UPF diet or an unprocessed diet for 2 weeks. Even though the calories were the same in the meals they were fed, those on the UPF diet ate 500 more calories a day and, after two weeks, had gained 0.9kg on average. They concluded that UPFs \u201clead people to overeat calories\u201d.<\/p>\n UPFs may also impact your gut microbiome, which can change in as little as 24 hours. \u201cSeveral small studies suggest reduced microbial diversity and a lower abundance of beneficial bacteria with these foods,\u201d says Lambert. \u201cCertain additives found in UPFs, such as emulsifiers and some artificial sweeteners, have also been shown in preliminary studies to alter gut barrier function and microbiota composition. However, this evidence is still emerging, and further research is needed to confirm the mechanisms and long-term effects in humans.\u201d<\/p>\n Beyond the gut, a UPF-heavy diet<\/a> over several weeks may begin to influence mood, metabolic responses, and body composition.<\/p>\n Five swaps to reduce UPFs in your diet<\/p>\n Swap Warburton\u2019s Protein Flatbreads for Crosta & Mollica Piandina Organic Wholeblend Italian Flatbreads<\/p>\n Don\u2019t be fooled by the promise of added protein. Many flatbreads contain high amounts of preservatives and stabilisers to keep them pillowy soft.<\/p>\n Swap Tony\u2019s Chocolony for Montezuma\u2019s Dark Chocolate<\/p>\n Most chocolate is incredibly high in UPFs because of all the stabilisers. Dark chocolate tends to be much lower, however, and Montezuma\u2019s is minimally processed.<\/p>\n Heinz Tomato Soup for Daylesford Organic Slow Roast Tomato & Mascarpone Soup.<\/p>\n Tinned soups often contain acidity regulators, not to mention lots of sugar and salt. Opt for fresh, organic options when you can.<\/p>\n Swap Sun-Pat Smooth Peanut Butter for Biona Organic peanut butter<\/p>\n It\u2019s the sneaky stabiliser (E471) in Sun-Pat that gives their peanut butter UPF status. Biona\u2019s version contains nothing but nuts.<\/p>\n Swap Hellman\u2019s Real Mayonnaise for Hunter & Gather\u2019s Classic Olive Oil Mayonnaise<\/p>\n Lots of mayo contains extra additives and flavourings that aren\u2019t strictly necessary. Look for ones with a shorter ingredient list.<\/p>\n \u201cAlthough significant metabolic changes are unlikely within a single month for healthy individuals, subtle shifts in energy regulation, digestive function, and mood are plausible when UPFs dominate the diet,\u201d adds Lambert. <\/p>\n After a year \u2013 high cholesterol and blood pressure, poor immunity and concentration<\/p>\n \u201cAfter a year of consistently high UPF intake, the body may begin to show more measurable and cumulative effects,\u201d says Lambert. \u201cDiets dominated by UPFs are strongly associated with an increased risk of insulin resistance, high blood pressure, and elevated LDL cholesterol, all of which are risk factors for cardiometabolic disease.\u201d<\/p>\n Over time, a lack of nutritionally-dense foods can also contribute to micronutrient deficiencies, she warns, particularly in iron, magnesium, folate, and other B vitamins, which may lead to fatigue, reduced immunity, or impaired concentration.<\/p>\n The daily spikes in blood sugar and fats add up over the course of a year and could lead to prediabetes. Around a quarter of people with prediabetes develop type 2 diabetes within five years<\/a>. A Spanish study that analysed the diets of 20,000 people, then followed up on participants\u2019 health 12 months later, found that those with the highest intake of UPF consumption had a 53 per cent higher risk of new-onset type 2 diabetes within the year. <\/p>\n As for other side effects? \u201cIn terms of food additives, most substances used in food processing, such as emulsifiers, stabilisers, and artificial sweeteners, are metabolised by the liver and excreted by the kidneys or digestive system, and do not remain in the body,\u201d says Lambert. \u201cHowever, repeated exposure over time may still influence health. Some animal studies and early-stage human data suggest that certain additives may impair gut barrier integrity, contribute to low-grade intestinal inflammation, or alter the gut microbiota. These mechanisms may help explain some of the observed links between UPF-rich diets<\/a> and chronic health conditions, but more research is needed to understand these effects in humans.\u201d<\/p>\n After decades \u2013 rise in cancer risk, cognitive decline<\/p>\n The lung cancer study linked UPF and lung cancer risk after looking at data over 12 years, suggesting a decade of reliance can have huge health side effects. \u201cOver a ten-year period, habitual consumption of UPFs has been associated with a significantly higher risk of chronic disease,\u201d says Lambert.<\/p>\n For instance, a 10-year study<\/a> found that those who sustained a high UPF intake had an increased risk of cardiovascular disease and coronary heart disease. Plus, a literature review that looked at studies on more than 63 million participants who were followed for between two and 27 years found the risk of cardiovascular disease escalated with UPF intake, and cardio-cerebrovascular disease increased by 7 per cent with an UPF intake of up to one serving per day.<\/p>\n \u201cIn terms of cancer risk, processed meats \u2013 a common UPF<\/a> \u2013 have been linked to an increased risk of colorectal cancer,\u201d says Lambert. \u201cA major UK study found a 32 per cent higher risk in people consuming around 80 grams of processed and red meat daily compared to those consuming under 11 grams.\u201d<\/p>\n Other forms of UPFs, such as sugary beverages and ultra-processed snack foods, are being studied for potential links to breast, pancreatic, and liver cancers. \u201cThis is an active area of research, and while some associations have been observed, more high-quality studies are needed to determine causality,\u2019 says Lambert.<\/p>\n Long-term intake of UPFs has also been linked to faster cognitive decline, with one Brazilian study showing a 25 per cent acceleration in decline among high-UPF consumers. \u201cThese risks are influenced by many factors, including genetics, physical activity, and other lifestyle habits, but the consistency of associations across multiple studies indicates that UPFs can play a role <\/a>in long-term health outcomes.\u201d<\/p>\n How to undo the damage\u00a0<\/p>\n If you\u2019ve spent years eating convenient foods rather than cooking from scratch, don\u2019t panic. \u201cThe body has a remarkable capacity to adapt and repair, even after many years of less-than-ideal dietary patterns. Making positive changes to your eating habits today can support long-term health and reduce the risk of future disease,\u201d says Lambert. <\/p>\n Eating whole foods, with plenty of fruit, vegetables, nuts and legumes, and cooking from scratch as much as possible is the simplest route to better health and gut health, she says. \u201cOne well-researched area is the gut microbiome, which can be supported through dietary diversity, particularly by increasing the variety of plant-based foods. Other effective strategies include preparing more meals at home using basic ingredients, even if that starts with just a couple of meals per week. Frozen and canned options can be convenient and affordable ways to include more whole foods. Physical activity, stress management, sleep, and hydration are all important in supporting recovery from previous poor eating habits.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"Research is showing that highly processed foods can impact everything from our mood to our risk of cancer…\n","protected":false},"author":2,"featured_media":64409,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[45],"tags":[242,1991,102,6636,56,7653,54,55],"class_list":{"0":"post-64408","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-nutrition","8":"tag-features","9":"tag-food","10":"tag-health","11":"tag-nutrition","12":"tag-uk","13":"tag-ultra-processed-food","14":"tag-united-kingdom","15":"tag-unitedkingdom"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts\/64408","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/comments?post=64408"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts\/64408\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/media\/64409"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/media?parent=64408"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/categories?post=64408"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/tags?post=64408"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"\"](\"https:\/\/www.newsbeep.com\/uk\/wp-content\/uploads\/2025\/08\/SEI_261929000.jpg\")
<\/p>\n![\"\"](\"https:\/\/www.newsbeep.com\/uk\/wp-content\/uploads\/2025\/08\/SEI_261840984.jpg\")
UPFs are addictive, and seem to have similar effects on the brain as alcohol and nicotine, experts have warned (Getty)<\/p>\n![\"Montezumas](\"https:\/\/www.newsbeep.com\/uk\/wp-content\/uploads\/2025\/08\/SEI_247754601.jpg\")
The 74 per cent cocoa bar is minimally processed (Photo: Montezuma\u2019s)<\/p>\n![\"Rhiannon](\"https:\/\/www.newsbeep.com\/uk\/wp-content\/uploads\/2025\/08\/PRI_216726967-e1755014291640.jpg\")
Dietitian Rhiannon Lambert says a highly processed diet can, over time, have serious effects on health, but it is possible to repair the damage (Photo: Frances Gizauskas)<\/p>\n