Guest Essay by Kip Hansen — 4 January 2025 — 1000 words/4 minutes
Prologue: This is a new entry to a series-of-many which have discussed ongoing scientific controversies, a specific type of which are often referred to in the science press and elsewhere as “Wars” – for instance The Monarch Wars, The Meat Wars, The Obesity Epidemic, The Salt Wars, The War in Sugar and the Great Barrier Reef Wars.
All of these controversies, these scientific wars, share common features which I laid out in Modern Scientific Controversies Part 5: Common Elements”.
The War on Food could stand as an exemplar for all of the controversies – and, in fact, it over laps with three of the previously covered Wars: The War on Sugar, The Meat War and The Obesity Epidemic.
Note: This piece is just a short introduction into the multi-part series on Ultra-processed Foods, UPFs. There will be several more similarly short essays in this series.
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The nutrition and food news today, including radio, TV, blogs, is full of stories decrying the consumption of Ultra-Processed Foods – UPFs. Normally I would give a series of links to the latest headlines but I doubt anyone could have missed them – they have been ubiquitous. Here is one typical piece, asking the main question: Ultraprocessed Foods: Are They Bad for You?
The YaleMedicine article refers to a number of recent review papers in major journals and uncritically quotes or paraphrases their conclusions in statements such as: “A review, published in the British Medical Journal (BMJ) in 2024, looked at 45 studies involving almost 10 million participants. The review authors suggest that eating more ultraprocessed foods is linked to a higher risk of dying from any cause and has ties to 32 health conditions, including heart disease, mental health disorders, type 2 diabetes, and other problems”.
The “review” mentioned is Lane et al. 2023 [ pdf here ], which comes with a link to the BMJ Editorial “Reasons to avoid ultra-processed foods”. The editorial includes this statement:
“The quality of the evidence was strong for all cause mortality, obesity, and type 2 diabetes (this evidence was rated as of moderate quality using the GRADE system, which initially considers all observational studies as low quality evidence). Overall, the authors found that diets high in ultra-processed food may be harmful to most—perhaps all—body systems.”
The authors of the study report their findings like this:
As an introduction to this whole topic, let’s just examine the actual evidence found in Lane et al. 2024 and compare it to the characterization from the BMJ and the authors’ conclusion. I supply the figures from the paper, annotated, along with two explanatory graphics on evidence strength.
Let me attempt a more pragmatic, unbiased interpretation of those two tables of findings:
Every item highlighted in Yellow indicates reasons to doubt the validity of the finding, for the following reasons:
1. Odds ratios (ORs) of a magnitude of 1.02 to 1.07 are vanishingly small and are doubtfully of any significant, real world importance – and certainly are not Minimal Clinically Important Differences.
2. In all charts, any highlighted finding with Confidence Interval whiskers that include “1”, there is no significant difference – or, in plain English, “nothing done” and the effect cannot be considered either positive or negative. These individual finding should not be included in any overall result of the study and not combined with other findings for an “overall score”.
3. Studies with a GRADE rating [“a method used to assess the quality of evidence in research studies”] of Low or Very Low do not return “strong evidence”, they produce low or very low quality evidence.
4. Findings of Studies with a Credibility Score of III, IV and V are not actually evidence. They are restatements of summaries [and as we shall see are often inaccurate summaries] about the evidence found in other systematic reviews and are prone to be what John P.A. Ioannidis describes as “simply accurate measures of the prevailing bias.”
5. All Cause Mortality is neither caused nor prevented exclusively by diet. An Odds Ratio as low as 1.02 (1.01 to 1.03) is not likely to be a significant result considering the multitude of possible confounders.
There is one interesting finding in Lane 2024 that warrants a closer look: the mental health finding. The ORs are high enough to be something but the GRADE rating of the studies used are low. I would want to dig in there and see which way the Arrow of Causation is pointing – do mental/emotional problems cause increased eating of UPFs or does the eating of more UPFs cause the mental/emotional health issues. Observational studies such as these cannot answer that question, they only find an association.
We will see this same pattern repeated through all the major systematic reviews of the UPF issue: Tiny ORs/HRs, ORs/HRs with CIs that include ‘1’, studies included in reviews even though they are of Low and Very Low quality, low Credibility Scores due to type of study, studies that measure a vague, not agreed upon, shifting and ill-defined range of foods – labeled UPFs – and results claimed for a broad heterogeneous range of foods.
The next essay in this series will cover: The Shifting and Indefinite Definition of UPFs.
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Author’s Comment:
I am trying a new thing by keeping the essays in this series short enough to be read by the average reader with limited time. The result will be several shorter essays, around 1000 words, with a reading time of 4 or 5 minutes. Let me know in comments (start with “Kip – “) if this is better or not. The upside is that more readers can actually read the entire piece if they are interested. The downside is that the shorter essays will cover a limited part of the whole topic – leaving lots of questions that will have to be (hopefully) answered in subsequent essays.
Lane et al. 2024 does have some findings that may be interesting to researchers. But is uses language in the conclusion referring to “the strongest available evidence” for evidence from studies that are acknowledged to be of Low and Very Low quality. Such evidence is Not Strong (or Strongest) – it may be the “strongest” of a lot of weak evidence, but it should be so stated. Lots of weak evidence just does not add up to strong evidence.
These large observational studies can raise interesting questions but cannot and do not supply any definitive answers.
Next in this series will try to answer the question: What is Ultraprocessed Food, exactly?
Thanks for reading.
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Kip: Thank you very much. I like the shorter segments. Thank you also for the salient points.
Kip – Thanks for the approach on article length. In high school I was always very satisfied if I could complete reading a SciAM article (this was in the 60’s). After a while they dumbed it down to the point where it became boring and a waste of time.
However, your articles have exhibited great quality over too much content (noise), which is a good sign.
Keep up the good work.
Yirgach ==> Thanks …and I agree about SciAm.
Kip – Another advantage to shorter articles is that when you have fewer point in the article, the discussion can be more focused.
MarkW ==> One can only hope — but as you know, the crowd here at WUWT is not all that good on focusing, they think too much and get ahead of the game (which is a good thing).
I plan to ignore this article’s conclusions.
Ultra-pasteurized milk is considered an ultra-processed food.
I was raised on raw milk straight from the cow, we drank it at every meal, and I was often miserable but did not know why.
Lactose-free did not solve my problem, but ultra-pasteurized does.
Ultra-pasteurized means heated to a minimum of 280°F for at least 2 seconds.
My current hypothesis is that heating milk breaks down some of the proteins.
If the store has no ultra-pasteurized milk, then as soon as I get it home, I cook it.
Cynthia ==> Confused…my conclusions or the study featured in this essay? But you are right — long-life milk is what you are talking about right? — ultra-pasteurized milk is considered a UPF. And, for many, ultra-pasteurized milk is the only safe milk available in their country.
You’ll have to wait for the next part to see just how illogical the defintion of UPFs is.
How long would i live not eating?. How long would i live eating UPFs?.
Mark ==> Longer with UPFs than nothing…..In the next part, you’ll see the list.
The causality problem is obviously huge with pre-made meals and dishes (which UPF is largely referring to). They are very disproportionately eaten by poor people and lazy people, characteristics which have their own sometimes profound impacts on health.
This would be very difficult to control for. Even if you did a study comparing people who tried to switch from TV dinners to cooking of unprocessed meats and vegetables, there would still be the confounding factor that the people who can make such a switch are highly motivated, unless you’re planning on hiring chefs for them.
Observational studies will never be able to get around causality and confounders.
Here is an example UPF wheat milling to flour https://images.app.goo.gl/gc3heBUVRTFiQfX57. Its been going on for very long time. https://images.app.goo.gl/gc3heBUVRTFiQfX57
Do you remember how vitamin B1 was discovered?
No until now just read the wiki https://en.wikipedia.org/wiki/Thiamine Thanks it was processing
It appears that if it taste’s good then avoid eating it! When I was young we were considered poor, living in public housing, and our diet was really constricted to things like chipped beef gravy and toast, and other foods that that were affordable to a family of 5. we became affluent to a degree when my father became an electrician and had full time employment. When this occurred our diet changed considerably and so did our weight. So to me most of this is garbage heaped upon us by those who want to control every aspect of our lives. While it may be true that some could be harmful when consumed in large quantities, for the most part though it is a joke!
Consumption of UPFs is being pushed as a cause of the excess deaths that have occurred following the mass jabbing experiment. Anything to deflect attention from the truth.
Kip: Thanks for yet another interesting post and promise of more to come on this theme. I appreciate the effort to keep a manageable size but my two cents is that you should not feel too constrained by the 1,000 word target if you find that keeping ideas together in one longer post might make for a better exposition. I am much more likely to read a 3,000 word article on a subject of interest than to follow links to two previous 1,000 word articles within the most recent 1,000 worder. Although being a regular WUWT reader I am also likely to have caught the previous 1,000 worders when they were posted.
It appears to me the western world is fast dividing into people who are willing to read/listen/view longer formats and people who are only willing (able?) to do extremely short formats – a bimodal distribution with little in the middle. For the latter group anything longer than a meme requires special effort. For the former group the difference between 500 and 2,500 words (if well written) is only if they have enough time on hand (e.g. coffee break), less so a limit of attention span or comprehension of complex ideas built upon each other. I would assert that most WUWT posts are already in the “long” category, appropriately so, and serving as a sort of pre-filter of audience expectation to gives you latitude for longer formats.
Thanks for the chance to provide feedback. Whatever makes sense to you and the editorial team is what I will happily read.
Best of the new year to you and yours.