The evidence that UPFs are bad for health is much, much stronger than the evidence for any candidate mechanism. There are lots of candidate mechanisms.
So I don't think anybody knows why they're bad. Surely the UPF classification includes lots of foods that are harmless. We just don't know which ones because we don't understand the mechanism.
Right but this is one of the major challenges with converting this information into actionable nutritional advice.
We have this (reasonably) rigid definition that grants the appearance of specificity. But there are almost surely UPFs that are fine and there are probably non-UPFs that cause the same problems as UPFs. Potato chips are hyper palatable, but are not UPFs.
So what is the benefit of saying "avoid UPFs" over "avoid junk food?" At least saying "avoid junk food" makes the fuzziness apparent. But by focusing on this UPF definition (which is almost surely not the actual thing that is causing negative health outcomes) we end up in weird scenarios where potato chips and bean-to-bar chocolate are fine but wheat bread with preservatives are not even if it turns out that the preservatives aren't the source of any problem.
> We have this (reasonably) rigid definition that grants the appearance of specificity. But there are almost surely UPFs that are fine and there are probably non-UPFs that cause the same problems as UPFs.
Not "almost" or "probably"; both are certain: Any description of reality fails on those standards. Always, there are exceptions and edge cases: 'We have this (reasonably) rigid definition that grants the appearance of specificity. But there are almost surely X that are fine and there are probably non-X that cause the same problems as X.'
To meet your standards, we would need a list of every food and its status - and that couldn't be created without impossibly extensive research.
That's why humans use imperfect models and categories - reality is too complex. The most specific, usable category seems to be 'ultra-processed foods'.
> So what is the benefit of saying "avoid UPFs" over "avoid junk food?"
Good question. Both categorizations will be flawed, but maybe UPF is a better fit or easier for people to understand.
Actually, according to the Nova Wikipedia page, the packaging of potato chips would push them into UPF. The actual, non-edible bag with the slogans and other soothsayings.
Where do you see that? My understanding is that packaging has to actually be implied by the food. It would be psychotic for potato chips served in a paper bag to be okay and potato chips served in a branded bag to be bad but I've been surprised before.
It is the case that several of the prominent voices against UPFs have said some ridiculous things in this direction. Like that a packaged lasagna that is made entirely from ingredients and processes that a home cook would use to make lasagna is bad because it comes from the same corporations and market forces that also produce the frozen lasagnas that are loaded with stabilizers and added sugar.
There have been several cases of possible or confirmed endocrine disruptors in food packaging, such as phthalates and bisphenol-A. My personal opinion is that those probably will turn out to have been harmless, but concerns over them aren't psychotic.
The bags normally used for potato chips are laminated from typically about four layers, one of which is a vacuum coating of aluminum and another of which is polyethylene terephthalate which has been strained to work-harden it, and hermetically sealed with industrial machinery that heats the bag to the melting point of its innnermost layer, typically with an inert atmosphere inside.
Potato-chip bags are probably the most sophisticated packaging used for any food you see routinely.
That does not, of course, mean that they are bad for you.
If there is no understanding of mechanisms, why put such a strong emphasis on the processing, and why organize them?
I, and other people argue that it has nothing to do with the processing and it’s all about the ingredients. So the whole differentiation by “processing” amount is useless. We are talking about ingredients without wanting to say so.
Processing is important. It's well known that that the grinding of flour has significant digestion effects, especially in diabetics. It takes a lot longer to digest a bulgur wheat salad than a slice of bread made with finely ground flour. This time difference makes a massive difference in insulin response.
The addition of ingredients is the processing. The different levels of processing refer to what types and quantities of ingredients are added. It's like complaining that people are labelling food as poisoned when they should really be concerned about whether it contains poison.
Likewise the categorization of processing is useful for exactly the same reason the category of poisoned is useful. I'd rather not consume poisoned food of any variety even if I'm uncertain which poison has been added to it.
Ok, maybe you're right, but can you categorize those and show that link?
Yes, the UPF classification used here likely flags some false positives and perhaps misses others, but if the methodology is otherwise sound and the link is there, even if fuzzy, I don't think it's as easy as you claim either. And even if if fuzzy, it's still useful as I would be healthier avoiding UPF (assuming accurate study), even if I would also avoid some perfectly healthy foods.
Just like other parts of science, that organization can be discussed and tested. It’s the opposite of “we asked the King what foods we can be most proud of”.
Linnaeus did this, and allowed himself to be wrong, and I argue his organization alone was necessary to talk about theory.
Every time i turn on the stove my kitchen catches on fire. I can't point out whats wrong with my stove, so obviously I keep the stove in my kitchen since I can't say it's causing the fire with a specific malfunction.
It reminds me of tobacco again. All these smokers, coughing up lungs, dying of lung/throat cancers, gee I wonder if it’s correlated? I knew when I was a kid and everyone in my family smoked it was unhealthy, it’s just obvious, how it was denied and people believed it for so long baffles me
Does this mean vegetable-based replacements for meats are going to experience reduced demand given they might be worse for health and more expensive than their meat counterparts?
They certainly meet the ultra processed foods criterion.
They might be worse or better for health, but they will probably be cheaper. They do certainly qualify as UPFs, since we don't know which ingredients, if any, are responsible for the health problems.
I don’t get the downvotes, this is a good question. I would prefer that the meat substitute market is allowed unbounded processing; and that the mere addition of nitrates to meat categorizes it into the terminal ultra-processed category.
If it turns out that xanthan gum causes metabolic syndrome, xanthan gum in meat substitutes will probably still cause metabolic syndrome, regardless of what you would prefer to allow.
Nitrates in meat cause stomach cancer (another thing we can't undo by legislative fiat) but probably don't cause the global pandemic of metabolic disease.
I mean, we know for a fat that processed red meats cause 'metabolic syndrome' - that being, the associated diseases of heart disease, diabetes, and others. One of the best ways to lower your CVD risk is to reduce your red meat consumption.
And, since I know it's inevitably coming, 'humans have been eating meat forever!' - no they absolutely have not:
1. Processed meats are a new thing. There is a difference between eating a cow, and taking cow meat and chemically changing it forever.
2. Farmed meat is a new thing. Prehistoric humans ate meat that is nothing like the meat we eat.
3. Eating meat is a new thing. For almost all of human history, until maybe ~50 years ago, humans ate very little meat. Even today, only the West eats high amounts of meat. We also only see metabolic syndrome in obesity in the West/the developed world. Do with that information what you will.
> Metabolic syndrome is a clustering of at least three of the following five medical conditions: abdominal obesity, high blood pressure, high blood sugar, high serum triglycerides, and low serum high-density lipoprotein (HDL).
The pandemic of obesity and metabolic syndrome started about 50 years ago, and is not limited to "the West" or "the developed world". Mass consumption of meats processed with nitrites (producing nitrates as a byproduct) goes back at least several centuries, maybe a millennium.
"Farmed meat", if by that you mean factory-farmed meat, is facially plausible as a cause, in that it fits the timeframe. However, people with metabolic syndrome who switch to an all-meat diet, even if the meat is factory-farmed, tend to improve rather than worsening.
Your definition of metabolic syndrome matches mine, I think you're talking past me. It's the clustering of metabolic diseases, like heart disease and obesity.
> Mass consumption of meats processed with nitrites (producing nitrates as a byproduct) goes back at least several centuries, maybe a millennium.
Incorrect, at least in what you mean by 'mass'. We eat significantly more meat now than 50 years ago.
> However, people with metabolic syndrome who switch to an all-meat diet, even if the meat is factory-farmed, tend to improve rather than worsening.
There's a few huge, glaring problems here:
1. You made this up, this isn't actually the conclusion of any study anywhere.
2. Any restrictive diet, yes ANY, can and will cause you to lose weight and therefore work against 'metabolic syndrome' (which, again, is not a disease, it's a syndrome). Yes, eating less calories WILL cause you to lose weight. You can achieve the same thing by eating only sugar, or only bread, or only cheese.
3. We know, for a fact, that diets with high meat consumption are correlated with obesity, heart disease, etc. We know diets LOW in meat consumption, particularly red meat or meat high in saturated fats, are correlated with lower CVD risk and longer longevity. Do with that what you will.
And, if you still don't buy many decades of studies on this, you can also just use your intuition.
Look around the world at where we see obesity and where we don't. We see it in the UK, Canada, the US. We don't see it in Japan, parts of Asia, and the Mediterranean. What's the difference?
Those places have a culture of eating significantly less meat, especially red meat. They also have a culture of eating smaller portions. Many of them have a culture of walking. Many of them still eat processed foods.
And, none of this even touches on the carcinogenic factors of red meat. We know, for sure, red meat is carcinogenic - it's classified the same as alcohol and tobacco.
Really what's going on is people are trading off stuff they think might be bad for stuff we know is bad.
There's a lot of people who won't drink a diet coke because it's 'poison' but will happily eat bacon. When we know bacon causes cancer, but we don't know if aspartame does, despite us studying it to death.
It's a form of self destruction. People think to be healthy you must deprive yourself, you must suffer. It's just not true.
So I don't think anybody knows why they're bad. Surely the UPF classification includes lots of foods that are harmless. We just don't know which ones because we don't understand the mechanism.