Eating more highly-processed foods may increase the risk of cancer, a study by a group of mainly French researchers has suggested.

The researchers, mostly from Paris 13 University in the French capital, said that a 10 percent increase in the proportion of "ultra-processed foods" in the diet was associated with a "significant increase" of more than 10 percent in the risk of cancer.

The ultra-processed foods they considered included soft drinks, mass-produced packaged bread and desserts, ready meals, instant noodles and soups, meatballs, and chicken and fish nuggets.

The study, published in British medical journal The BMJ, was carried out on 104,980 people who had enrolled online in a French research program on links between diet and health.

The researchers warned that the results would have to be confirmed by further large-scale studies in different populations and settings.

According to a 2017 study using the same definition of ultra-processed foods, the average household availability of such foods in 19 European countries ranged from 10.2 percent in Portugal and 13.4 percent in Italy to highs of 46.2 percent in Germany and 50.4 percent in Britain.

That study, published in the journal Public Health Nutrition, said there was a "significant positive association" between availability of such foods and obesity.