How does Ultra-Processed Food impact our health, food insecurity and environment?

Over the last decade, prospective studies have consistently found associations between consumption of UPFs and a wide range of chronic diseases as well as all-cause and cause-specific mortality. 

Higher consumption of UPFs is indeed associated with higher risks of cardiovascular, coronary heart, and cerebrovascular disease.

Numerous studies have also shown an association between UPFs consumption and higher risks of cancers. A European study from the EPIC cohort showed that the substitution of 10% of ultra-processed foods with 10% of minimally processed foods was associated with a reduced risk of head and neck cancers, colon cancer and hepatocellular carcinoma. In a French study, a 10% increase in the proportion of UPFs in the diet was associated with a more than 10% increase in the risk of developing cancer overall, and breast cancer in particular. Scientists from the International Agency for Research on Cancer (IARC) suggest that the replacement of ultra-processed foods and drinks with an equal amount of minimally processed foods and drinks may reduce the risk of various cancer types. 

Prospective studies from various European cohorts (EPIC across Europe, SUN in Spain, NutriNet-Santé in France) have revealed an association between UPFs consumption and a higher risk of overweight and obesity. The European cohort study EPIC, with participants from 9 countries across Europe, showed highest UPFs consumption was associated with a 15% greater risk of becoming overweight or obese in normal weight participants, and with a 16% greater risk of becoming obese in participants who were overweight at baseline. An American study led in randomized controlled conditions showed that, between two diets adjusted for their nutritional profiles, participants on the ultra-processed diet ate an extra 500 calories a day, resulting in an average weight gain of 1kg in 2 weeks!  

Several studies similarly showed that a higher proportion of UPFs in the diet was associated with a higher risk of type 2 diabetes. A European study based on the EPIC cohort investigated the relationship between the degree of food processing and type 2 diabetes risk, including which kinds of UPFs were most high-risk. The team analysed UPFs intake and health outcomes for 311,892 individuals from eight European countries. They found that every 10% increase in the amount of UPFs in a person’s diet is linked with a 17% increase in type 2 diabetes risk, but this risk can be lowered by consuming less-processed foods instead.  

French Inserm researchers found a significant association between high consumption of UPFs and the risk of recurrence of depressive symptoms. Participants who consumed the most UPFs (i.e. 1/3 of their total intake) had a 30% increased risk of recurrent depressive symptom episodes, compared with participants whose share of UPFs in daily intake was less than 1/5. UPFs have been shown to promote oxidative stress and inflammation, and to alter gut microbiota and genome expression, which are known to impact mental health. These results are corroborated by an Australian meta-analysis that highlighted increased odds of depressive and anxiety symptoms when consuming greater amounts of UPFs.  

Other health impacts have been less investigated but might also be modulated by the consumption of UPFs such as chronic insomnia, chronic kidney disease, irritable bowel syndrome or functional dyspepsia. An Italian study pointed out a diet rich in UPFs was associated with an acceleration of biological aging in a sample of Italian adults, as measured by blood-based biomarkers, Moreover, no study reported any association between consumption of UPF and beneficial health outcomes! 

French Food Safety Agency Anses conducted a systematic review of the scientific studies published on this topic. Experts confirmed, albeit with a low weight of evidence, that a higher level of consumption of foods classified as ultra-processed under the NOVA framework is associated with a higher risk of mortality and chronic diseases such as type 2 diabetes, overweight, obesity, cardio neurovascular diseases, and breast and colorectal cancer. 

All these data strongly suggest that recommendations to limit UPFs consumption may be beneficial to health, though further mechanistic studies are needed. 

Many UPFs contain what are called “empty calories”: it means they are deficient in vital nutrients (such as fibre, vitamins, minerals) and excessive in fat, sugar, sodium. They don’t provide satiety while being hyperglycaemic. This leads both to overnutrition (overweight and obesity) and undernutrition (micronutrients deficiencies). Unfortunately, several studies show higher intakes of UPFs have been observed in low-income populations, for instance in the United-States, which contributes to higher risks of obesity and cardiometabolic diseases. 

Similarly, an English study examined how snacking habits develop through families of different socioeconomic backgrounds and the factors influencing them. It highlights that ultra-processed, high-fat, -salt, and -sugar snacks (HFSS) contribute to rising obesity rates and nutritional disparities. Families integrate infants into existing snacking habits early on, with lower-income parents favouring UPFs and HFSS snacks due to affordability, convenience, and marketing tactics. Wealthier families can more easily provide fresh fruit, which lower-income families see as a financial burden. The study also notes misleading marketing of "healthier" snacks with similar nutritional profiles to HFSS options. 

UPFs intake is associated with public health inequalities which emphasises the urgent need for policy action to minimise social injustice-related health inequalities. 

As this article from The Conversation puts it: “Ultra-processed foods are not only bad for our bodies, their production damages our environments”. In a French study based on the Third French Individual and National Food Consumption survey, overall UPFs represented 19% of the diet yet contributed 24% to the diet’s greenhouse gas emissions, 23% to water use, 23% to land use and 26% to energy demand. Compared with low consumers of UPFs, high consumers consumed more caloric energy (+22%), which partially explained the higher environmental pressures. After adjusting for calories consumed, the associations with greenhouse gas emissions and land use vanished, and the associations with water use and energy demand became negative. However, the processing and packaging stages contributed significantly to energy demand. Post-farm stages contribute greater environmental impacts of UPFs-rich diets.  

Indeed, manufacturing processes and long supply chains undeniably raise the environmental footprint of the diet. Palm oil is quite emblematic of how widespread industrial use of a specific ingredient can negatively affects the environment: it remains the world’s most consumed vegetable oil although being responsible for deforestation of some of the world’s most biodiverse forests. 

UPFs consumption also significantly contributes to agrobiodiversity loss. The globalised diet linked with UPFs is characterised by an abundance of branded foodstuffs distributed on an industrial scale, that comes at the expense of the cultivation and consumption of traditional foods, comprising mostly fresh and minimally processed foods. UPFs use ingredients extracted from a few high-yielding plant species (such as maize, wheat, soy and oil seed crops). They tend to encourage a homogenization of agricultural landscapes at the detriment of historical and more diverse production systems cultivating grains, pulses, fruits and vegetables. Animal-sourced ingredients used in many UPFs are often derived from confined animals fed on the same crops. 

Finally, waste generated by over-packaged UPFs is another negative externality to consider. UPFs are often packaged in plastic materials that consist of a cocktail of chemicals and can leach harmful substances such as phthalates and bisphenols, especially when heated or stored for long periods: the damages caused by such migrations are highly underestimated, with some thousands of chemicals from plastics migrating into foodstuffs. This raises concerns about the long-term cumulative health risks arising from people’s combined exposures to both the chemical additives in the food itself and the contaminants from its packaging. Plastic packaging can also have a dramatic impact on soil health and marine life. Paper-based food contact materials, often perceived as greener and safer, also contain harmful substances such as PFAS (per- and polyfluoroalkyl substances), which are added for grease resistance and may migrate into UPFs, further compounding potential health risks. 

Behind this mass production stand multinational industrial conglomerates with a vested interest in ensuring that the appetite for ultra-processed food continues unabated.