Back to Home11/19/2025, 9:15:38 AM

Ultra-processed food linked to harm in every major human organ, study finds

62 points
67 comments

Mood

thoughtful

Sentiment

negative

Category

science

Key topics

health

nutrition

food science

A study found that ultra-processed food is linked to harm in every major human organ, highlighting the potential health risks of such foods.

Snapshot generated from the HN discussion

Discussion Activity

Active discussion

First comment

3h

Peak period

16

Hour 5

Avg / period

7

Comment distribution28 data points

Based on 28 loaded comments

Key moments

  1. 01Story posted

    11/19/2025, 9:15:38 AM

    10h ago

    Step 01
  2. 02First comment

    11/19/2025, 11:46:05 AM

    3h after posting

    Step 02
  3. 03Peak activity

    16 comments in Hour 5

    Hottest window of the conversation

    Step 03
  4. 04Latest activity

    11/19/2025, 3:06:34 PM

    4h ago

    Step 04

Generating AI Summary...

Analyzing up to 500 comments to identify key contributors and discussion patterns

Discussion (67 comments)
Showing 28 comments of 67
TheAceOfHearts
7h ago
3 replies
In case anyone wants a proper definition: ultra-processed food is defined using the Nova classification system [0]. I still find the definition a bit confusing though.

This is the outcome of having researchers dedicating multiple lifetimes towards optimizing food to be as palatable and optimized as possible, such that people are forced to have a self-control battle each meal. Maybe GLP-1 drug proliferation will force companies towards other optimization goals. We ultimately end up paying for the negative externalities of UPF through higher healthcare costs and overall worse long-term quality of life.

It's difficult to change and maintain healthy eating habits when so much of your environment is designed to push you towards foods with questionable health properties. Even if it's technically possible to eat healthy, the cognitive overhead is enough that individualistic solutions are always going to be limited in effectiveness. The ideal is living in an environment where the healthy options are the default choice, so you don't have to waste time, energy, and willpower on maintenance-level tasks. I imagine that a healthier population would also be more productive, for the number-go-up optimizers.

[0] https://en.wikipedia.org/wiki/Nova_classification

_aavaa_
7h ago
2 replies
My problem with it is that it’s a circular definition without a mechanism for why they are bad for health.

Discussions I’ve seen for why they are bad always basically boil down to “it’s the ingredients” without wanting to say this.

randycupertino
4h ago
I'd guess it's twofold: 1.) Lack of fiber in the ultra processed foods 2.) shelf-stability additives so the food can sit on shelves for months and not go bad.
kragen
6h ago
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.

general1465
7h ago
5 replies
Yeah the whole definition is bogus. i.e. "mechanically separated meat" is considered ultraprocessed food? Why? By this logic putting apples into mixer and creating pyre is ultraprocessed food too.
lentil_soup
5h ago
Apples are actually a great example.

Think of eating an apple vs drinking apple juice. The amount of entire apples you can drink is immense compared to eating the apple whole. So the mechanical process does affect how we consume the food.

Concrete3286
5h ago
Seems like a reasonable definition? It's not referring to tissue you put through a grinder yourself.

From wikipedia:

Mechanically separated meat (MSM), mechanically recovered/reclaimed meat (MRM), or mechanically deboned meat (MDM) is a paste-like meat product produced by forcing pureed or ground beef, pork, mutton, turkey or chicken under high pressure through a sieve or similar device to separate the bone from the edible meat tissue. When poultry is used, it is sometimes called white slime as an analog to meat-additive pink slime and to meat extracted by advanced meat recovery systems, both of which are different processes. The process entails pureeing or grinding the carcass left after the manual removal of meat from the bones and then forcing the slurry through a sieve under pressure.

The resulting product is a blend primarily consisting of tissues not generally considered meat, along with a much smaller amount of actual meat (muscle tissue).

macNchz
5h ago
Does anybody eat mechanically separated meat as-is? I imagine it’s basically only available to end users as a final product like chicken nuggets or hot dogs, mixed with many additives.
_aavaa_
7h ago
And even if you want to define it as such, why is that bad for health?
throwaway89201
5h ago
I'm not sure you are replying knowing what "mechanically separated meat is", as it isn't just cutting / separating pieces of regular meat using machinery. It's the sieving of a ground up bone/flesh mix into a meat paste. The result product is not something you would normally call meat, and called 'white slime' by some.
jhallenworld
5h ago
I always assumed ultra-processed means that the food is loaded with preservatives like phosphates or BHT. I guess that's part of it, but maybe the efficiency of digestion should be considered. I remember Ben Krasnow (Applied Science) measured the calories in poop, humans are not very efficient at extracting all calories leading to very likely large efficiency variance between foods. But extending this further, the calories lost during preparation should be accounted for...

So how about: calories * digestion-efficiency - calories you personally need to expend to prepare or acquire it. The higher this number, the more processed is the food. So cane sugar is very bad, unless you personally harvested it.

Bad news for highly paid programmers.. basically all food should be considered ultra-processed since no physical labor was needed to acquire it.

iammjm
6h ago
2 replies
Weird choice of the image by TheGuardian: there's some obviously highly processed foods such as doughnuts and candy, but you also have french fries, popcorn and even some nuts there. The text itself doesn't elaborate on this much either. What is it exactly that I am supposed to avoid?
Lord-Jobo
6h ago
3 replies
The easy answer that encompasses 99% of the target foods is:

Avoid any foods that involve multiple rounds of processing, a term that includes baking, frying, adding preservatives,sugars or oils. Generally, if it has a lot of sugar or oil and has a weirdly long shelf life, be suspicious.

Drift towards: easily washable (smooth/peelable) fruits and vegetables, 100% whole wheat bread products, simple meat products like whole animal parts or deboned animal parts.

Dairy lives in the middle ground. If you have zero lactose problem, most dairy is mostly okay, just watch for sugar levels and recognize that most dairy products are calorie dense. Nuts are in this group too for the same reason but oil instead of sugar.

Bonus points for consuming real pro and pre biotics when you can. In the United States this is pretty limited to live culture yogurts, refrigerated kimchi, and refrigerated sourkraut.

Jensson
5h ago
Popcorn is just 1 round of cooking though, you can fry them yourself at home, its less processing than bread.
glitchc
5h ago
Hang on. Pickling and fermentation are multi-step processes to transform food into their final state. Moreover, pickling is expressly used for preservation and long shelf life. Why are they not considered "ultra-processed" according to this definition? As you point out, they are an integral part of a healthy diet in multiple cultures.
z500
5h ago
What's wrong with baking?
AdmiralAsshat
5h ago
2 replies
> but you also have french fries, popcorn and even some nuts there

For popcorn at least, I'd assume it's the prepackaged microwavable popcorn that gets flagged as UPF, where it's encased in hydrogenated oils, salt, and preservatives. It's hard to think that popcorn you make at home could be considered UPF, considering that it's literally one ingredient with heat applied to it (and oil I guess if you're popping it on the stovetop rather than an air fryer).

randerson
5h ago
Microwave Popcorn containers are also coated with PFAs.
zug_zug
4h ago
Yeah ever heard of popcorn lung? Crazy stuff
skeezyjefferson
6h ago
3 replies
why was this flagged?

imagine just buying normal food that wasnt done on the cheap. nobody could afford to live. even in usa, richest country in the world, people are eating cheap crap, living in wooden houses... of course you can be the richest country in the world if you just lower your living standards perpetually

ranger_danger
5h ago
1 reply
Probably because "ultra-processed" is a bogus definition that doesn't prove what exactly is unsafe or why, which the authors of the study even acknowledge directly in the article:

> Critics argue UPF is an ill-defined category and existing health policies, such as those aimed at reducing sugar and salt consumption, are sufficient to deal with the threat.

> Monteiro and his co-authors acknowledged valid scientific critiques of Nova and UPF – such as lack of long-term clinical and community trials, an emerging understanding of mechanisms, and the existence of subgroups with different nutritional values.

It's not "processing" in itself that is causing problems, there is something specific (possibly a set of common ingredients used in many such foods) that we just haven't identified yet as what the actual harm is, so people lump all processed food into the harmful category and tell people to just stay away from all of it, which is not a realistic solution given current food production practices.

zug_zug
4h ago
Sounds like those people are having an irrational emotional response to a term rather than addressing the presented research in good faith.

Also being a broad or nebulous category doesn’t make it not science… much of what science studies starts broad and nebulous or even theoretical.

iammjm
5h ago
dafuq is "normal" food? if by normal you mean usual or typical for a supermarket, then that would be mostly highly processed foods full of sugars and fats. Now that I think about it, what one actually wants is the not-normal foods, the raw unprocessed minority
moi2388
5h ago
I buy normal food and it’s plenty cheap tbh
WesolyKubeczek
5h ago
Is there some clear boundary where a food stops being just processed and starts to be ultraprocessed?
smusamashah
4h ago
I just found that the bread is also considered ultra processed food (and hence not healthy?). https://en.wikipedia.org/wiki/Ultra-processed_food

This seems shocking a bit. If bread is a UPF, there will be a lot more items we never even think about.

RamblingCTO
4h ago
I have always found it so weird to go to a supermarket when you have a (somewhat) "clean" diet. I go from veggies and fruits to meat and dairy and then I'm out again. 95% of the shelves I don't even look at.

Also, the definition of (ultra) processed food isn't so hard: just buy original food, not extrapolations of that. Buy veggies and potatoes, not chips. Buy meat, not sausages or burgers. Buy an apple and yoghurt, not the yoghurt you can buy off the shelf. Just basic ingredients.

Isamu
6h ago
Discussion about this tends to get hung up on the relative harm of a particular food, let’s say a donut. But the article is really about a diet that is dominated by food like donuts.

>Evidence reviewed by 43 of the world’s leading experts suggests that diets high in UPF are linked to overeating, poor nutritional quality and higher exposure to harmful chemicals and additives.

>This category is made up of products that have been industrially manufactured, often using artificial flavours, emulsifiers and colouring. They include soft drinks and packaged snacks, and tend to be extremely palatable and high in calories but low in nutrients.

>They are also designed and marketed to displace fresh food and traditional meals, while maximising corporate profits, Monteiro said.

39 more comments available on Hacker News

ID: 45977457Type: storyLast synced: 11/19/2025, 3:42:03 PM

Want the full context?

Jump to the original sources

Read the primary article or dive into the live Hacker News thread when you're ready.