What are they measuring? – Watt?

Guest post by Kip Hansen — January 18, 2024 — 400 words/5 minutes

According to the American Medical Association, in an article in JAMA's “What Doctors Want Their Patients to Know™” series:

“Research shows that a diet rich in ultra-processed foods is linked to more than 30 health conditions, according to a comprehensive review of meta-analyses published in the British Medical Journal. At the same time, greater exposure to ultra-processed foods is associated with a higher risk of death from any cause. . It is also strongly linked to higher consumption and cardiovascular disease-related deaths, mental health disorders and type 2 diabetes.

This statement is based on many published comments nutritional epidemiology research (hundreds). In 2024 alone, 45 review studies or meta-analyses on UPF were published.

Nutritional epidemiology?

World-class statistician William “Matt” Briggs, author of this book “Uncertainty: The Soul of Modeling, Probability, and Statistics,” tell usunequivocallyThat:

“Epidemiology is a field that formally mistakes correlation for causation.”

This is a very serious allegation. This is also true. And it's getting worse. This is a consequence of the definition and practice of nutritional epidemiology:

“Nutritional Epidemiology

Nutritional epidemiology is the application of epidemiological methods to study the relationship between diet and human health and disease at the population level. … Epidemiologists study how nutrition affects the occurrence of disease by collecting data and comparing large groups of people. Statistical methods are used to estimate the extent to which a factor affects a population's risk of disease. This estimate is often expressed as a measure of correlation.

“In epidemiological studies, diet can be studied at different levels, including the intake of nutrients, foods, food groups and/or patterns. These exposures can be achieved by directly determining what people eat (e.g., through questionnaires), through Measured by measuring uptake markers in biological samples or by estimating body size and relative sizes of body compartments.

“The exposure measure of interest in nutritional epidemiology is typically long-term diet, as the effects of intake on most health outcomes, particularly those related to non-communicable diseases, are likely to occur over longer periods of time.”

The chapter is summarized from Encyclopedia of Food and Health, 2016, It reads more concisely:

“Nutritional epidemiology is the application of epidemiological methods to study the relationship between diet and human health and disease at the population level. This article reviews key issues in the field of nutritional epidemiology, including the description of methods for assessing dietary intake, sources of dietary variation, the relevance of total energy intake to epidemiological analyses, and errors that may occur when measuring dietary exposure.

The problems of nutritional epidemiology immediately become apparent:

1. “…study the relationship between diet and human health and disease at the population level.”

If these population-level relationships When trying to apply to individuals we encounter ecological fallacy: A logical error that occurs when assumptions are made about individuals based on group data.

2. “… This estimate—the extent to which a factor affects disease risk in a population—is often expressed as a measure of association.

The measure of correlation, of correlation, is not risk, but statistics. The real risk comes from exposure to causal factors and its dosageTo do this, researchers need to measure the dose received by individuals exposed to the hypothesized chance factor. Hypothesized causal factors need to be supported by biological plausibility.

For UPF, something like for the purpose of certain processing steps or business ownership Food manufacturers' products cannot be, and are not, biologically plausible contributors to the myriad negative effects of consuming UPF.

3. “…These exposures can be measured by directly determining what people eat (for example, through questionnaires)…”

exposure can be Direct measurement, but food frequency questionnaire (FFQ) and 24-hour dietary recall (24 hours) does not directly measure the exposure or dose of food in a person's diet. They are, at best, vague estimates of dietary intake. Many nutritional epidemiology studies are based on a single “last year…” type food frequency questionnaire. Or even a 24-hour dietary recall. These FFQs are then treated as real-world exposures and doses. Typically, participants are then assumed to maintain the same eating habits for the next several years and, in some cases, decades.

4. “The exposure measure of interest in nutritional epidemiology is usually long-term diet,…”

As mentioned above, exposure to a measure of benefit (in this case, UPF) is almost never actually measured in any scientifically defensible way. Moreover, apart from one or two clinical trials, the practical dose is no way Measurement.

5. “…Sources of dietary variation”… “and possible errors in measuring dietary exposure.”

People's diets don't stay the same for years and decades. And eating is a very difficult thing measure outside of institutional settings. Changes in marital status, age, becoming a parent, moving from university to professional life, changes in financial status, changes in employment, moving from one region or country to another – all these and many more factors directly change our The eating habits of most people in their daily lives.

How does all this apply to the study of ultra-processed foods?

exist Modern Scientific Controversy: Food Wars: Part 2, What is UPF? We see that this title question is difficult to answer definitively. This definition is vague and based on factors unrelated to nutrition, relying primarily on “NOVA Food Group: Definition Based on Scope and purpose of food processing“,For example Purpose Processing steps used in food manufacturing: ensuring product longevity, taste, palatability, pleasant texture, etc.

For this reason, what dietary items are included in the dietary questionnaire? [FFQs/24HRs] What counts as UPF in various research efforts changes over time and is often subjective [as in “influenced by or based on personal beliefs or feelings, rather than based on facts”] So every study is different.

Not all items on the UPF list are different foods with different characteristics. nutritious Quality – Nutritional value is not considered in the definition. Items in a UPF checklist have no common ingredients. Items in the UPF checklist do not share common processes. Many anti-UPF arguments contain a heavy dose of anti-transnational corporatism.

In fact, the entire subject is not scientifically suitable for research. To be scientifically sound, it must be measurable that the dose level of the food (or food group) to which the study participants will be or have been exposed is measurable, and, if multiple foods are considered a group, the foods must be measurable of.

It's impossible to measure the “use” or “multinational corporate ownership” of the various items sold in grocery stores. There are no acceptable measures of these concepts. It's impossible to measure the relative “UPF” of items sold in grocery stores, such as these ubiquitous grocery store breads:

we can only scientifically right dose received The specific dietary items of interest and the dosages to be measured. Dosage is not a binary measure—not yes/no.

Even known poisons are dose dependent – some benefit from small doses but are lethal from larger doses – this is called hormesis.

All UPF prospective cohort and observational studies (cross-sectional, case-control and cohort) as well as reviews and meta-analyses, even the large-scale umbrella review of epidemiological meta-analyses ( Lane et al., 2024 ) suffer from the well-described More mistakes than.

What is the result of all this?

A pseudoscientific fad—the anti-UPF movement—has almost become infectious

All levels of the world of health and nutrition science.

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Author comments:

Let me put it as bluntly as possible: the anti-UPF movement is pure “fashion science.” It wastes countless research dollars supporting an ideological battle against food produced by multinational corporations because they share fabricated ideas. bad things hide in some way exist “Scope and purpose of food processing”.

Some voices are trying to stem the tide of condemnation of all UPF.

It’s important to understand that UPF does not mean junk food. This is a completely different concept and classification.

UPF is also not the same as food containing “additives” or “artificial colors” or “preservatives” – even if a food lacks these, it can still be classified as UPF.

UPF is a catch-all classification that basically includes “almost everything sold in a grocery store in a package, bag, or box.”

The anti-UPF movement is a food war.

Thank you for reading.

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