Higher consumption of ultra-processed food is consistently associated with more cardiovascular disease, diabetes, obesity, depression, cancer and earlier death, spread across dozens of health outcomes. The associations are large and wide-ranging, but the underlying studies are almost exclusively observational and of moderate to low quality, so causality has not yet been definitively established.
Ultra-processed food (abbreviated UPF) is food that has been heavily industrially processed and typically contains many additives such as emulsifiers, sweeteners, flavour enhancers and artificial colourings. Think of soft drinks, bags of crisps, ready-made meals, factory bread and cheap processed meats. A large umbrella review covering nearly 10 million people examined 45 different health outcomes: in 32 of those 45 outcomes (71%), higher UPF consumption was associated with greater harm to health. The harm extended across the cardiovascular system, metabolism, mental health, respiration, the gut and cancer (PMID 38418082, 35658669).
The links are most strongly documented for the most serious consequences. People with the highest UPF intake have a 50% greater risk of dying from cardiovascular disease (RR 1.50) and a 21% greater risk of dying prematurely from any cause (RR 1.21). The risk of type 2 diabetes also increases: every 10% increase in UPF as a share of the daily diet is associated with a 12% higher chance of diabetes, and those who consistently eat large amounts of UPF have a 40% higher chance compared with low consumers (PMID 38418082).
The associations are also strikingly large for obesity and mental health. High UPF consumption is associated with a 55% greater chance of obesity. For anxiety disorders the figure is 48% higher risk, and for general psychological complaints as high as 53%. Prospective research, in which people are followed over a longer period, shows that eating a lot of UPF is also associated with a 22% greater chance of developing depression later in life. Causality has not yet been proven here, but the pattern is consistent (PMID 38418082, 35807749).
There are also indications of higher rates of cancer, sleep problems, bowel diseases and respiratory problems. For every 10% increase in UPF in the diet, the overall cancer risk rises by 13%; for pancreatic cancer that figure rises to as much as 49% higher risk. Colorectal cancer and breast cancer likewise show elevated risks. For gut conditions such as inflammatory bowel disease and irritable bowel syndrome, the evidence remains primarily observational for now; the role of specific additives has so far been demonstrated mainly in animal and laboratory studies (PMID 37087831, 38418082, 38388570).
In children and young people the picture is similar: regular UPF consumption is associated with more obesity, more sedentary behaviour and an early elevated risk of chronic diseases such as cardiovascular disease and dental problems. Eating breakfast regularly and getting sufficient exercise are most strongly associated with lower UPF use in this age group (PMID 37866398).
An important caveat: virtually all available studies are observational. This means that researchers look at who eats a lot of UPF and whether those people become ill more often, but this does not yet prove a direct cause. People who eat a lot of UPF may also have other unhealthy habits that influence the results. The GRADE quality assessment of the underlying studies is predominantly low to very low. This makes the associations found concerning, but caution in interpretation remains warranted.
Based on one large umbrella review (PMID 38418082, ~10 million participants) and additional systematic reviews/meta-analyses (PMID 35807749, 35658669, 37087831, 38388570, 37866398). All studies are observational; randomised intervention trials are largely absent. GRADE quality is predominantly low to very low.