Food is full of chemicals and always has been. After all, everything is chemicals. But modern 'ultraprocessed' food is something else again – and new research suggests it could be more harmful than we suspect.

A massive new study by scientists in France examining the dietary intake of over 44,000 French adults found that consumption of ultraprocessed foods – including mass-produced snacks, sugary drinks, and ready-made meals – was associated with a higher risk of mortality over the study period.

"Ultraprocessed foods are food products that contain multiple ingredients and are manufactured through a multitude of industrial processes," researchers, led by nutritional epidemiologist Laure Schnabel from Sorbonne University, explain in their paper.

"These food products are usually ready to heat and eat, affordable, and hyperpalatable."

Convenient and tasty they may well be, but consumption of ultraprocessed foods – which also include highly processed breads, plus confectioneries and processed meats – is known to be problematic, having already been tied to higher risk of things like obesity, hypertension, and cancer.

Up until now, though, nobody had separately assessed whether eating ultraprocessed foods also made you more likely to die.

In the studied cohort, however, it did.

Over a period of over seven years, a 10 percent increase in the proportion of ultraprocessed food consumption was linked with a 14 percent higher risk of all-cause mortality.

The research team is eager to emphasise that the study was only observational, so a causative effect cannot be shown. But the fact that a statistically significant association was found is something to think about.

"We shouldn't be alarmist, or say that eating a packaged meal gives you a 15-percent higher chance of dying," Mathilde Touvier, the co-investigator of the NutriNet-Santé cohort they studied, told AFP.

"It's another step in our understanding of the link between ultraprocessed food and health."

What is certain is that ultraprocessed foods contain lots of things you don't find in whole foods: all kinds of additives, including preservatives, sweeteners, enhancers, colours, flavours, and so on.

They also contain a lot of energy – in the study, accounting for 14.4 percent of the total weight of food and drink consumed, but 29.1 percent of total energy intake.

Ultraprocessed foods are also consumed disproportionately more by individuals with lower incomes or education levels, or those who live alone, according to epidemiologist Nita Forouhi from the University of Cambridge, who wasn't part of the study.

"A vital take-away message is that consumption of highly processed foods reflects social inequalities," Forouhi says.

"Such foods are attractive because they tend to be cheaper, are highly palatable due to high sugar, salt and saturated fat content, are widely available, highly marketed, ready-to-eat, and their use-by-dates are lengthy, so they last longer."

As it stands, despite the robust size and duration of this particular research, there's a lot more work to be done to definitively unravel why and how ultraprocessed foods could be bad for us.

It's a job that's made significantly harder due to the multitude of food products we're talking about – not to mention the multitude of ingredients (artificial or otherwise) ultraprocessed foods contain.

"Some factors may be more harmful or less harmful than others. It's really too complex," nutritional scientist Nurgul Fitzgerald from Rutgers University, who wasn't involved with the research, told CNN.

But if you're particularly concerned about ultraprocessed foods, what's in them, and what they could be doing to you, the best approach may be going back to basics next time you're in the supermarket.

"Look at the ingredients list. Do you understand all those ingredients that go into your foods?" Fitzgerald said. "[Buy those] with the least number of ingredients and with ingredients you understand."

The findings are reported in JAMA Internal Medicine.