Tag: ultra-processed foods

Ultra-processed Foods Might Not Be the Real Villain in Our Diets – Here’s What Our Research Found

Photo by Andriyko Podilnyk on Unsplash.

Graham Finlayson, University of Leeds and James Stubbs, University of Leeds

Ultra-processed foods (UPFs) have become public enemy number one in nutrition debates. From dementia to obesity and an epidemic of “food addiction”, these factory-made products, including crisps, ready meals, fizzy drinks and packaged snacks, are blamed for a wide range of modern health problems. Some experts argue that they’re “specifically formulated and aggressively marketed to maximise consumption and corporate profits”, hijacking our brain’s reward systems to make us eat beyond our needs.

Policymakers have proposed bold interventions: warning labels, marketing restrictions, taxes, even outright bans near schools. But how much of this urgency is based on solid evidence?

My colleagues and I wanted to step back and ask: what actually makes people like a food? And what drives them to overeat – not just enjoy it, but keep eating after hunger has passed? We studied more than 3,000 UK adults and their responses to over 400 everyday foods. What we found challenges the simplistic UPF narrative and offers a more nuanced way forward.

Two ideas often get blurred in nutrition discourse: liking a food and hedonic overeating (eating for pleasure rather than hunger). Liking is about taste. Hedonic overeating is about continuing to eat because the food feels good. They’re related, but not identical. Many people like porridge but rarely binge on it. Chocolate, biscuits and ice cream, on the other hand, top both lists.

We conducted three large online studies where participants rated photos of unbranded food portions for how much they liked them and how likely they were to overeat them. The foods were recognisable items from a typical UK shopping basket: jacket potatoes, apples, noodles, cottage pie, custard creams – more than 400 in total.

We then compared these responses with three things: the foods’ nutritional content (fat, sugar, fibre, energy density), their classification as ultra-processed by the widely used Nova systema food classification method that groups foods by the extent and purpose of their processing – and how people perceived them (sweet, fatty, processed, healthy and so on).

Perception power

Some findings were expected: people liked foods they ate often, and calorie-dense foods were more likely to lead to overeating.

But the more surprising insight came from the role of beliefs and perceptions. Nutrient content mattered – people rated high-fat, high-carb foods as more enjoyable, and low-fibre, high-calorie foods as more “bingeable”. But what people believed about the food also mattered, a lot.

Perceiving a food as sweet, fatty or highly processed increased the likelihood of overeating, regardless of its actual nutritional content. Foods believed to be bitter or high in fibre had the opposite effect.

In one survey, we could predict 78% of the variation in people’s likelihood of overeating by combining nutrient data (41%) with beliefs about the food and its sensory qualities (another 38%).

In short: how we think about food affects how we eat it, just as much as what’s actually in it.

This brings us to ultra-processed foods. Despite the intense scrutiny, classifying a food as “ultra-processed” added very little to our predictive models.

Once we accounted for nutrient content and food perceptions, the Nova classification explained less than 2% of the variation in liking and just 4% in overeating.

That’s not to say all UPFs are harmless. Many are high in calories, low in fibre and easy to overconsume. But the UPF label is a blunt instrument. It lumps together sugary soft drinks with fortified cereals, protein bars with vegan meat alternatives.

Some of these products may be less healthy, but others can be helpful – especially for older adults with low appetites, people on restricted diets or those seeking convenient nutrition.

The message that all UPFs are bad oversimplifies the issue. People don’t eat based on food labels alone. They eat based on how a food tastes, how it makes them feel and how it fits with their health, social or emotional goals.

Relying on UPF labels to shape policy could backfire. Warning labels might steer people away from foods that are actually beneficial, like wholegrain cereals, or create confusion about what’s genuinely unhealthy.

Instead, we recommend a more informed, personalised approach:

• Boost food literacy: help people understand what makes food satisfying, what drives cravings, and how to recognise their personal cues for overeating.

• Reformulate with intention: design food products that are enjoyable and filling, rather than relying on bland “diet” options or ultra-palatable snacks.

• Address eating motivations: people eat for many reasons beyond hunger – for comfort, connection and pleasure. Supporting alternative habits while maximising enjoyment could reduce dependence on low-quality foods.

It’s not just about processing

Some UPFs do deserve concern. They’re calorie dense, aggressively marketed and often sold in oversized portions. But they’re not a smoking gun.

Labelling entire categories of food as bad based purely on their processing misses the complexity of eating behaviour. What drives us to eat and overeat is complicated but not beyond understanding. We now have the data and models to unpack those motivations and support people in building healthier, more satisfying diets.

Ultimately, the nutritional and sensory characteristics of food – and how we perceive them – matter more than whether something came out of a packet. If we want to encourage better eating habits, it’s time to stop demonising food groups and start focusing on the psychology behind our choices.

Graham Finlayson, Professor of Psychobiology, University of Leeds and James Stubbs, Professor in Appetite & Energy Balance, Faculty of Medicine and Health School of Psychology, University of Leeds

This article is republished from The Conversation under a Creative Commons license. Read the original article.

A ‘Non-industrialised’ Style Diet can Reduce Risk of Chronic Disease

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Researchers have found that a newly developed diet inspired by the eating habits of non-industrialised societies can significantly reduce the risk of a number of chronic diseases typical of processed, low-fibre industrialised diets – and are to share recipes with the public.

Their paper, published in Cell, shows that a newly developed diet that mimics eating habits in non-industrialised communities led to significant metabolic and immunological improvements in a human intervention study. In just three weeks the diet:

  • Promoted weight loss
  • Decreased bad cholesterol by 17%
  • Reduced blood sugar by 6%
  • Reduced C-reactive Protein (a marker of inflammation and heart disease) by 14%

These improvements were linked to beneficial changes in the participants’ gut microbiome, the home to trillions of bacteria that play a vital role in our health, influencing digestion, immunity, and metabolism. The research was conducted by an international teams of scientists led by Professor Jens Walter, a leading scientist at University College Cork. The human trial was performed at the University of Alberta in Canada, Prof Walter’s previous institution.

“Industrialisation has drastically impacted our gut microbiome, likely increasing the risk of chronic diseases.” explained Prof Walter, who is also a Principal Investigator at APC Microbiome Ireland, a world-renowned Research Ireland centre

“To counter this, we developed a diet that mimics traditional, non-industrialised dietary habits and is compatible with our understanding on diet-microbiome interactions. In a strictly controlled human trial, participants followed this diet and consumed L. reuteri, a beneficial bacterium prevalent in the gut of Papua New Guineans but rarely found in the industrialised microbiomes.”

The study demonstrated that the new diet entitled NiMeTM (Non-industrialised Microbiome Restore) diet enhanced short-term persistence of L. reuteri in the gut.

However it also improved microbiome features damaged by industrialisation, such as reducing pro-inflammatory bacteria and bacterial genes that degrade the mucus layer in the gut. These changes were linked to improvements in cardiometabolic markers of chronic disease risk.

Although participants did not consume fewer calories on the NiMe diet, they lost weight, and the diet alone led to considerable cardiometabolic benefits.

In previous research, Prof Walter’s team, studying the gut microbiome in rural Papua New Guinea, found that individuals there have a much more diverse microbiome, enriched in bacteria that thrive from dietary fibre, and with lower levels of pro-inflammatory bacteria linked to western diet. This information was used to design the NiMeTM diet.

The NiMeTM diet shares key characteristics of non-industrialised diets:

  • Plant-based focus, but not vegetarian: Primarily made up of vegetables, legumes, and other whole-plant foods. One small serving of animal protein per day (salmon, chicken, or pork).
  • No dairy, beef, or wheat: Excluded simply because they are not part of the traditional foods consumed by rural Papua New Guineans.
  • Very low in processed foods that are high in sugar and saturated fat.
  • Fibre-rich: Fibre content was 22 grams per 1000 calories – exceeding current dietary recommendations.

“Everybody knows that diet influences health, but many underestimate the magnitude”, said Prof. Walter.

Commenting on this study, Prof. Paul Ross, Director of APC Microbiome Ireland, said: “This study shows that we can target the gut microbiome through specific diets to improve health and reduce disease risk. These findings could shape future dietary guidelines and inspire the development of new food products and ingredients, as well as therapeutics, which target the microbiome”.

“The recipes from the NiMe Diet will be posted to our Instagram ( @nimediet ) and Facebook pages, and they will also be included in an online cookbook soon. It is important to us to make these recipes freely available so that everyone can enjoy them and improve their health by feeding their gut microbiome,” said Dr Anissa Armet from the University of Alberta, a registered dietitian that designed the NiMe diet and one of the lead authors of the publication.

Source: University College Cork

Study Links Emulsifiers and Type 2 Diabetes Risk

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Emulsifiers, commonly used additives for improving the texture of food products and extending their shelf life, may be associated with the onset of type 2 diabetes, according to a large cohort study of over 100 000 people in France.

Researchers from Inserm, INRAE, Université Sorbonne Paris Nord, Université Paris Cité and Cnam, as part of the Nutritional Epidemiology Research Team (CRESS-EREN), studied the possible links between the dietary intake of food additive emulsifiers and the onset of type 2 diabetes between 2009 and 2023. They analysed the dietary and health data of 104 139 adults participating in the French NutriNet-Santé cohort study, specifically evaluating their consumption of this type of food additive using dietary surveys conducted every six months. The findings suggest an association between the chronic consumption of certain emulsifier additives and a higher risk of diabetes. The study is published in Lancet Diabetes & Endocrinology.

In Europe and North America, 30 to 60% of dietary energy intake in adults comes from ultra-processed foods. An increasing number of epidemiological studies suggest a link between higher consumption levels of ultra-processed foods with higher risks of diabetes and other metabolic disorders.

Emulsifiers are among the most commonly used additives. They are often added to processed and packaged foods such as certain industrial cakes, biscuits and desserts, as well as yoghurts, ice creams, chocolate bars, industrial breads, margarines and ready-to-eat or ready-to-heat meals, in order to improve their appearance, taste and texture and lengthen shelf life. These emulsifiers include for instance mono- and diglycerides of fatty acids, carrageenans, modified starches, lecithins, phosphates, celluloses, gums and pectins.

As with all food additives, the safety of emulsifiers had been previously evaluated by food safety and health agencies based on the scientific evidence that was available at the time of their evaluation.
However, some recent studies suggest that emulsifiers may disrupt the gut microbiota and increase the risk of inflammation and metabolic disruption, potentially leading to insulin resistance and the development of diabetes.

For the first time worldwide, a team of researchers in France has studied the relationships between the dietary intakes of emulsifiers, assessed over a follow-up period of maximum 14 years, and the risk of developing type 2 diabetes in a large study in the general population.

The results are based on the analysis of data from 104 139 adults in France (average age 43 years; 79% women) who participated in the NutriNet-Santé web-cohort study (see box below) between 2009 and 2023.

The participants completed at least two days of dietary records, collecting detailed information on all foods and drinks consumed and their commercial brands (in the case of industrial products). These dietary records were repeated every six months for 14 years, and were matched against databases in order to identify the presence and amount of food additives (including emulsifiers) in the products consumed. Laboratory assays were also performed in order to provide quantitative data. This allowed a measurement of chronic exposure to these emulsifiers over time.

During follow-up, participants reported the development of diabetes (1056 cases diagnosed), and reports were validated using a multi-source strategy (including data on diabetes medication use). Several well-known risk factors for diabetes, including age, sex, weight (BMI), educational level, family history, smoking, alcohol and levels of physical activity, as well as the overall nutritional quality of the diet (including sugar intake) were taken into account in the analysis.

After an average follow-up of seven years, the researchers observed that chronic exposure – evaluated by repeated data – to the following emulsifiers was associated with an increased risk of type 2 diabetes:

  • carrageenans (total carrageenans and E407; 3% increased risk per increment of 100 mg per day)
  • tripotassium phosphate (E340; 15% increased risk per increment of 500 mg per day)
  • mono- and diacetyltartaric acid esters of mono- and diglycerides of fatty acids (E472e; 4% increased risk per increment of 100 mg per day)
  • sodium citrate (E331; 4% increased risk per increment of 500 mg per day)
  • guar gum (E412; 11% increased risk per increment of 500 mg per day)
  • gum arabic (E414; 3% increased risk per increment of 1000 mg per day)
  • xanthan gum (E415; 8% increased risk per increment of 500 mg per day)

This study constitutes an initial exploration of these relationships, and further investigations are now needed to establish causal links. The researchers mentioned several limitations of their study, such as the predominance of women in the sample, a higher level of education than the general population, and generally more health-promoting behaviours among the NutriNet-Santé study participants. Therefore caution is needed when extrapolating the conclusions to the entire French population.

The study is nevertheless based on a large sample size, and the researchers have accounted for a large number of factors that could have led to confounding bias. They also used unique, detailed data on exposure to food additives, down to the commercial brand name of the industrial products consumed. In addition, the results remain consistent through various sensitivity analyses, which reinforces their reliability.

“These findings are issued from a single observational study for the moment, and cannot be used on their own to establish a causal relationship,”explain Mathilde Touvier, Research Director at Inserm, and Bernard Srour, Junior Professor at INRAE, lead authors of the study. “They need to be replicated in other epidemiological studies worldwide, and supplemented with toxicological and interventional experimental studies, to further inform the mechanisms linking these food additive emulsifiers and the onset of type 2 diabetes. However, our results represent key elements to enrich the debate on re-evaluating the regulations around the use of additives in the food industry, in order to better protect consumers.”

Among the next steps, the research team will be looking at variations in certain blood markers and the gut microbiota linked to the consumption of these additives, to better understand the underlying mechanisms. The researchers will also look at the health impact of additive mixtures and their potential ‘cocktail effects.’

They will also work in collaboration with toxicologists to test the impact of these exposures in in vitro and in vivo experiments, to gather more arguments in favour of a causal link.

Desirability of Ultra-processed Foods no Better than Less Processed Ones

Photo by Skyler Ewing

New research that had participants compare the taste perception of less processed foods with ultra-processed foods (UPFs), found that UPFs were no more pleasant tasting than less processed foods. The University of Bristol-led findings, published in the journal Appetite, support the theory that humans are programmed to learn to like foods with more equal amounts of carbohydrate and fat. Carbohydrate (including sugars) and fat provide most of the calories in human diets.

The study wanted to test the common but largely untested assumptions that food energy density (calories per gram), level of processing, and carbohydrate-to-fat ratio are key factors influencing food liking and desirability.

In the experiment, involving 224 adult volunteers, participants were presented with colour images of between 24 and 32 familiar foods, varying in energy density, level of processing (including UPFs), and carbohydrate-to-fat ratio. There were 52 different foods in total, including avocado, grapes, cashew nuts, king prawns, olives, blueberry muffin, crispbread, pepperoni sausage, and ice cream.

Participants were then asked to rate the foods for taste pleasantness (liking), desire to eat, sweetness, and saltiness while imagining tasting them. The validity of this method was confirmed by, for example, finding a strong relationship between sweetness ratings and food sugar content.

Results from the study showed that, on average, UPFs were no more liked or desired than processed or unprocessed foods. But foods that combined more equal amounts (in calories) of carbohydrate and fat were more liked and desired than foods equivalent in calories but mostly from either carbohydrate or fat. This is known, from previous research, as the ‘combo’ effect.

Further results revealed that foods with higher amounts of dietary fibre were less liked and desired, and foods tasting more intense (mainly related to the level of sweetness and saltiness), were more liked and desired.

Lead author Professor Peter Rogers found the results for UPFs surprising.  He said: “Our results challenge the assumption that ultra-processed foods are ‘hyperpalatable’, and it seems odd that this has not been directly tested before.

“However, whilst ultra-processing didn’t reliably predict liking (palatability) in our study, food carbohydrate-to-fat ratio, food fibre content, and taste intensity did – actually, together, these three characteristics accounted for more than half of the variability in liking across the foods we tested.

“The results for sweetness and saltiness, are consistent with our innate liking for sweetness and saltiness. And the results for carbohydrate-to-fat ratio and fibre might be related to another important characteristic that determines food liking.

“Our suggestion is that humans are programmed to learn to like foods with more equal amounts of carbohydrate and fat, and lower amounts of fibre, because those foods are less filling per calorie. In other words, we value calories over fullness.

“In turn, this trait helps us to maximise calorie intake and build up fat reserves when food is abundant – which is adaptive in circumstances when food supplies are uncertain or fluctuate seasonally, but not when food is continuously available in excess of our immediate needs.”

The researchers at the Nutrition and Behaviour Group are currently testing the calories versus fullness idea in further studies of food liking and meal preferences, including across different countries and cuisines.

Source: University of Bristol

Ultra-processed Foods Linked to Mouth, Throat and Oesophagus Cancer Risk

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Eating more ultra-processed foods (UPFs) may be associated with a higher risk of developing cancers of the upper aerodigestive tract (ie, the mouth, throat and oesophagus), according to a new study in the European Journal of Nutrition. The authors of this study, led by the University of Bristol and the International Agency for Research on Cancer (IARC), say that obesity associated with the consumption of UPFs may not be the only factor to blame.

Several studies have identified an association between UPF consumption and cancer, including a recent study which looked at the association between UPFs and 34 different cancers in the largest cohort study in Europe, the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, which followed 450 111 adults who for approximately 14 years.

As more evidence emerges about the associations between eating UPFs and adverse health outcomes, researchers from the Bristol Medical School and IARC wanted to explore this further.

Since many UPFs have an unhealthy nutritional profile, the team sought to establish whether the association between UPF consumption and head and neck cancer and oesophageal adenocarcinoma in EPIC could be explained by an increase in body fat.

Results from the team’s analyses showed that eating 10% more UPFs is associated with a 23% higher risk of head and neck cancer and a 24% higher risk of oesophageal adenocarcinoma in EPIC.

Increased body fat only explained a small proportion of the statistical association between UPF consumption and the risk of these upper-aerodigestive tract cancers.

Fernanda Morales-Berstein, a Wellcome Trust PhD student at the University of Bristol and the study’s lead author, explained: “UPFs have been associated with excess weight and increased body fat in several observational studies. This makes sense, as they are generally tasty, convenient and cheap, favouring the consumption of large portions and an excessive number of calories. However, it was interesting that in our study the link between eating UPFs and upper-aerodigestive tract cancer didn’t seem to be greatly explained by body mass index and waist-to-hip ratio.”

The authors suggest that other mechanisms could explain the association.

For example, additives including emulsifiers and artificial sweeteners which have been previously associated with disease risk, and contaminants from food packaging and the manufacturing process, may partly explain the link between UPF consumption and upper-aerodigestive tract cancer in this study.

Fernanda Morales-Berstein and colleagues did caution that the associations between UPF consumption and upper-aerodigestive tract cancers found in the study could be affected by certain types of bias.

This would explain why they found evidence of an association between higher UPF consumption and increased risk of accidental deaths, which is highly unlikely to be causal.

Inge Huybrechts, Team head of the Lifestyle exposures and interventions team at IARC, added: “Cohorts with long-term dietary follow-up intake assessments, considering also contemporary consumption habits, are needed to replicate these study’s findings, as the EPIC dietary data were collected in the 1990s, when the consumption of UPFs was still relatively low. As such associations may potentially be stronger in cohorts including recent dietary follow-up assessments.”

Further research is needed to identify other mechanisms, such as food additives and contaminants, which may explain the links observed.

However, based on the finding that body fat did not greatly explain the link between UPF consumption and upper-aerodigestive tract cancer risk in this study, Fernanda Morales-Berstein, suggested: “Focussing solely on weight loss treatment, such as semaglutide, is unlikely to greatly contribute to the prevention of upper-aerodigestive tract cancers related to eating UPFs.”

Source: University of Bristol