Eating a family bag of chips every day could raise the risk of throat and mouth cancers by 25 percent, a study has suggested.

Researchers found cancer risk shot up when people ate just 350g of ultra-processed food per day over the course of a decade - the equivalent of a large packet of chips or half a sharing bag of Skittles.

This amount was linked to a 20 percent higher risk of head and neck cancer and a 25 percent higher risk of oesophageal adenocarcinoma, a type of cancer that grows in the lining of the food pipe.

Previous research has suggested that the link between cancer risk and junk food can be explained by the fact these high-calorie items can cause harmful weight gain.

However, the latest study makes an argument for an alternative mechanism, as excess weight was only a factor in a small proportion of cancer cases.

Instead the researchers, from the University of Bristol in the UK, say the disease could result from detrimental changes in gut flora, as well as potential hormonal effects. 

Dr David Katz, a specialist in preventive and lifestyle medicine who was not involved in the study, told CNN: 'If UPFs contribute to cancer risk, they do it to a small extent by contributing to obesity, and to a much larger extent by other mechanisms.

'What might those be? Diet-induced inflammation; disruption of the microbiome; adverse epigenetic effects; and many other possibilities come to mind.' 

Ultra-processed foods, such as sodas, chips, nuggets, candy and cakes, contain many ingredients, most of which are rarely used in kitchens. 

They also contain additives such as artificial colors and preservatives, which keep the food fresher for longer.

These types of foods are also often high in calories, sugar, salt and fat, increasing the likelihood of weight gain if eaten regularly. 

The new study, published in the European Journal of Nutrition, analyzed diet and lifestyle data of 450,111 adults participating in a broader European study.

Called the European Prospective Investigation into Cancer and Nutrition (EPIC), it is one of the largest studies in Europe and recruited participants between 1992 and 1999 from 23 centers across 11 European countries.

For the new paper, researchers looked at cancer incidences in participants with high processed food intake over the course of 14 years - and compared outcomes to those who ate little of it. 

Intriguingly, the larger waist-to-hip ratio - a measurement of obesity - only explained five percent of the 23 percent higher risk of head and neck cancer.

Meanwhile, an increase in body mass index (BMI) across the study period explained 13 percent of the additional risk for esophageal cancer, while waist-to-hip ratio explained 15 percent.

However, the findings do not show a direct cause - it is possible that other factors caused the increased cancer risk. Those who eat large amounts of junk food are also more likely to smoke and drink alcohol - known drivers of throat and mouth cancer.

Speaking of the findings, study lead Fernanda Morales Berstein told DailyMail.com: 'Replacing any amount of ultra-processed foods in the diet with less processed foods may decrease the risk of upper-aerodigestive tract cancer.'