Why we’ll never know the truth about ultra-processed food – BBC News

they is The black beast From many nutritionists – mass-produced foods like chicken nuggets, packaged snacks, flavored drinks, ice cream or sliced ​​brown bread.

UPF is defined by how many industrial processes they have gone through and the number of – often unpronounceable – ingredients in their packaging. Often high in fat, sugar or salt; Many would call you fast food.

What unites them is their synthetic look and taste, which has made them a target of some clean living advocates.

There is a growing body of evidence that these foods are not good for us. But experts can’t agree on exactly how or why they affect us, and it’s not clear that science will give us an answer anytime soon.

Recent research shows many widespread health problems, including cancer, heart disease, obesity and depression. is connected As for the UPF, there is still no evidence that they are caused By them.

For example, a recent meeting of the American Association for Nutrition in Chicago was presented with an observational study of more than 500,000 people in the United States. It found that those who ate the most UPF had an approximately 10% higher chance of dying early, even taking into account their body mass index and overall diet quality.

In recent years, many other observational studies have shown a similar connection—but not the same as proving it how Processed foods cause health problems, or determine which aspect of those processes is to blame.

So how do we get to the truth about highly processed foods?

Dr Nerys Astbury, a senior researcher in food and obesity at the University of Oxford, suggests that the study needed to definitively prove that UPF causes health problems would be extremely complex.

It would require comparing large numbers of people on two diets – one with a high UPF and one with a low UPF, but exactly matched for calories and macronutrient content. This would of course be very difficult to do.

Participants must be kept under lock and key so that their intake can be strictly managed. The study will also need to include people with a similar diet as a starting point. It will be extremely challenging logistically.

To counter the possibility that people who eat less UPF may have healthier lifestyles, such as exercising more or getting more sleep, participants in the groups should have very similar habits.

“It’s going to be expensive research, but you can see changes in diet relatively quickly,” says Dr Astbury.

Funding for this type of research can be difficult. Because researchers motivated to conduct these types of experiments may have an idea of ​​what the conclusions should be before they begin, there may be allegations of conflicts of interest.

These experiments can’t last very long, though—most participants will probably drop out. Telling hundreds of people to follow a strict diet for more than a few weeks is impractical.

However, what can these hypothetical experiments actually prove?

Duane Mellor, head of nutrition and evidence-based medicine at Aston University, says nutrition scientists can’t prove specific foods are good or bad, or what effect they have on a person. They can only show potential benefits or risks.

“The data doesn’t show more or less,” he says. Claims to the contrary are “poor science,” he says.

Another option would be to look at the effects of common food additives in UPFs on a lab model of the human gut – something scientists are busy doing.

However, there is a wider problem – the confusion surrounding what actually counts as UPF.

Usually, they include more than five ingredients, several of which can be found in an average kitchen cupboard.

Instead, they are usually made from cheap ingredients such as modified starches, sugars, oils, fats and protein isolates. Then, flavor enhancers, colors, emulsifiers, sweeteners and glazing agents are added to make them more appealing to the taste buds and eyes.

They range from the obvious (sugary breakfast cereals, sour drinks, slices of American cheese) to the sometimes more unexpected (supermarket hummus, low-fat yogurt, some mueslis).

And this raises questions: How useful is a label that puts chocolate bars in the same league as tofu? Can some UPF affect us differently than others?

To find out more, BBC News spoke to the Brazilian professor who coined the term “ultra-processed food” in 2010.

Professor Carlos Monteiro also developed the Nova classification system, which ranges from “whole foods” (such as legumes and vegetables) at one end of the spectrum through “processed culinary ingredients” (such as butter) to “processed foods” (such as canned tuna and salted peas) up to UPF.

Professor Monteiro thought the system was developed after Brazil’s obesity rate continued to rise as sugar consumption fell. He believes that our health is not only affected by the nutrient content of the food we eat, but also by the industrial processes used to make and preserve it.

He says the current massive focus on UPF was unexpected, but he claims it “contributes to a paradigm shift in nutrition science.”

However, many nutritionists say the fear of UPF is overheated.

Gunter Kuhnle, professor of nutrition and dietetics at the University of Reading, says the concept is “vague” and the message it sends is “negative” and makes people feel confused and fearful about food.

It is true that there is currently no definitive evidence that the way food is prepared harms our health.

Processing is something we do every day – cutting, boiling and freezing are all processes and those things are harmless.

When manufacturers process food at scale, it helps ensure food is safe, preserved for longer and waste is reduced.

Take frozen fish fingers for example. They use leftover fish scraps, give kids healthy meals and save parents time – but they still count as UPF.

What about meat replacement products like Quorn? Sure, they don’t look like the original ingredients they’re made from (and therefore fall under the UPFs definition of Nova), but they’re considered healthy and nutritious.

“If you make a cake or a brownie at home and compare it to one that already comes in a packet of flavor enhancers, do I think there’s a difference between the two foods? No, I don’t,” Dr. Asbury tells me.

The Food Standards Agency, the body responsible for food safety in England, acknowledges reports that people who eat more UPF are at increased risk of heart disease and cancer, but says it will take no action on UPF until it has evidence. Deals specific damage.

Last year, the Government’s Scientific Advisory Committee on Nutrition (SACN) looked at the reports and concluded that there were “uncertainties about the quality of the available evidence”. It also had some concerns about the practical use of the Noah system in the UK.

For his part, Professor Montero is more concerned about processes involving intense heat, such as the production of breakfast cereal flours and puffs, which he claims “degrade the natural food matrix”.

He points to a small study that suggests this leads to a loss of nutrients and therefore makes us feel less full, meaning we’re more willing to make up for the deficit with extra calories.