The BBC reports that researchers in France and Spain say that what are known as ultra-processed foods – such as instant soups, ice cream and breakfast cereals – have been linked to early death and poor health and the amount of such food being eaten has soared.
Their studies are not definite proof of harm but experts expressed caution and called for further investigation.
In a study by the University of Navarra, in Spain, 19,899 people were followed for a decade and assessed their diet every other year.
There were 335 deaths during the study.
But for every 10 deaths among those eating the least ultra-processed food, there were 16 deaths among those eating the most (more than four portions a day).
In another study by the University of Paris, followed 105,159 people for five years and assessed their diet twice a year.
It showed those eating more ultra-processed food had worse heart health.
Rates of cardiovascular disease were 277 per 100,000 people per year among those eating the most ultra-processed food, compared with 242 per 100,000 among those eating the least.
Dr Mathilde Touvier, from the University of Paris, told BBC News: “The rapid and worldwide increasing consumption of ultra-processed foods, to the detriment of less processed foods, may drive a substantial burden of cardiovascular diseases in the next decades.”
Ultra-processed foods, are categorized as those which have been through more substantial industrial processing and often have long ingredient lists on the packet, including added preservatives, sweeteners or colour enhancers.
Prof Maira Bes-Rastrollo, from the University of Navarra, told BBC News: “It is said that if a product contains more than five ingredients, it is probably ultra-processed.”
processed meat such as sausages and hamburgers
breakfast cereals or cereal bars
sugary fizzy drinks
many “ready to heat” meals such as pies and pizza
Prof Bes-Rastrollo, from the University of Navarra, told BBC News she was “very certain” they were bad for health.
The challenge is being 100% sure.
The studies have spotted a pattern between highly processed food and poor health but they cannot prove that one causes the other.
Those who ate the most ultra-processed food were also more likely to have other unhealthy behaviours, such as smoking, which the researchers tried to account for.