How bad is ultra-processed food, and what does it do to you?
People who consistently eat large amounts of ultra-processed food have, on the basis of large observational studies, a considerably higher risk of cardiovascular disease, diabetes, obesity and premature death. The associations are broad and consistent, but a direct causal link has not yet been definitively proven.
Ultra-processed food (UPF) is heavily industrially processed food containing many additives: emulsifiers, sweeteners, flavour enhancers and artificial colours. Think fizzy drinks, crisps, ready meals, factory bread and cheap processed meats. A comprehensive umbrella review covering nearly 10 million people examined 45 health outcomes. In 32 of them (71%), higher UPF consumption was associated with greater health harm, ranging from cardiovascular disease to cancer and mental health1,2.
The greatest risks are linked to cardiovascular disease and premature death. People who eat the most UPF have a 50% higher chance of dying from cardiovascular disease and a 21% higher chance of dying early from any cause. Every 10% increase in UPF as a share of daily food intake is associated with a 12% higher risk of type 2 diabetes. Consistently eating large amounts of UPF is associated with as much as a 40% higher risk of diabetes compared with low consumers1.
The figures for weight and mental health are also strikingly large. High UPF consumption is associated with a 55% higher risk of obesity. For anxiety disorders the figure is 48% higher risk, and for general psychological complaints 53%. People followed over the long term developed depression 22% more often if they ate a lot of UPF. Causality has not yet been proven here, but the pattern is consistent1,3.
There are also indications of higher rates of cancer, sleep problems and gut disorders. For every 10% increase in UPF, total cancer risk rises by 13%; for pancreatic cancer that figure climbs to 49%. For gut conditions the evidence is still largely observational, and the role of specific additives has been demonstrated mainly in animal and laboratory studies4,1,5.
An important caveat: almost all studies are observational. They show who eats a lot of UPF and who falls ill more often, but that does not prove a direct cause. People with high UPF diets may also have other unhealthy habits. The quality assessment of the studies is predominantly low to very low. The associations are worrying and consistent enough to take seriously, but hard evidence from randomised trials is still lacking.
Based on one large umbrella review (PMID 38418082, ~10 million participants) and additional systematic reviews and meta-analyses (PMID 35807749, 35658669, 37087831, 38388570, 37866398). All studies are observational; randomised trials are largely absent. Quality assessment is predominantly low to very low.