Diets that include "ultra-processed" ready-to-eat meals may increase the risk of premature death, research suggests.
Scientists in France who studied a large population of more than 44,500 men and women aged 45 and older, discovered a strong link between bad eating and dying.
Every 10 percent increase in ultra-processed food consumption was associated with a 14 percent greater risk of death from any cause.
Participants in the study provided information about their eating habits, lifestyle and socio-economic background before they followed their progress for seven years.
Ultra-processed food was defined as food manufactured by multiple industrial processes and usually consumed in the form of snacks, desserts or ready-made meals or heat meals.
Examples include chicken nuggets, preserved meat products, packaged snacks and instant noodle soup meals.
During the follow-up period researchers recorded 602 deaths – 1.4 percent of the total group. These include 219 deaths caused by cancer and 34 by heart and artery disease.
The scientists, led by Dr. Laure Schnabel from the University of Paris-Sorbonne, wrote in the journal Jama Internal Medicine: "An increase in the consumption of ultra-processed food seems to be associated with an overall higher mortality risk in this adult population.
"Further prospective studies are needed to confirm these findings and to unravel the various mechanisms by which ultra-processed food can affect health."
Consumption of prepared meals and other forms of ultra-processed food accounted for an average 29 percent of total caloric intake, the study found.
It was also associated with younger age, poorer training, life alone, lower physical activity and higher body weight.
These and other factors were taken into account by the researchers.
There may be different explanations for the findings, the scientists said.
Some ultra-processed foods contain large amounts of salt and a high sodium intake was associated with higher rates of cardiovascular disease and gastric cancer.
Excessive sugar in the diet was also linked to a greater risk of death from cardiovascular disease.
In addition, ultra-processed food contains few fibers, which have been shown to reduce the mortality risk.
Food additives, often found in ultra-processed foods, can also play a role, according to the researchers.
For example, titanium dioxide was widely used by the food industry but was associated with inflammatory bowel disease and cancer.
There was also evidence that consumption of emulsifiers could have an effect on gut bacteria and would promote cancer and metabolic syndrome, a pre-diabetic condition.
British statistician Professor Kevin McConway, of the Open University, warned that French findings may not apply to the UK.
He said: "The diet of people in the United Kingdom differs greatly from that in France and in the UK we eat (on average) much more in the area of foods classified as ultra-processed, but we probably also eat different types ultra-processed foods, and indeed different types of foods that are not ultra-processed.
"Since this study does not provide data on which aspects of food can cause problems, it may be that the findings are not transmitted to the UK at all – we simply can not say."
Professor Nita Forouhi, from the University of Cambridge, said: "The case against highly processed food is increasing, with this study contributing significantly to a growing number of evidence for the health damage of ultra-processed foods.
"Although this research is observational, with well-known limitations, the authors have made demonstrable attempts to reduce it, but there are still some important limitations." – PA