Why Eating a Healthy Diet is Incredibly Easy and Completely Impossible

When it comes to diet tidy answers are appealing. Carbs are the problem, or maybe it’s fat. Maybe The healthiest diet is to eat no meat at all, or to eat nothing but ribeyes slathered in lard with a side of bacon. Or maybe it’s important to focus on including foods that are particularly healthy, like olive oil and blueberries, red wine, coffee, chocolate, acai, whole grains, liver, and on and on. Or maybe the key is a specific compound, like omega-3 acids or fiber or resveratrol or raspberry ketones.

Unfortunately, these are all wrong. While it is certainly the case that different people may be healthier on one of these diets or on another, there is no evidence that any of them can explain why rates of type 2 diabetes, metabolic disorders, cardiovascular disease, gout, and all the other so-called diseases of civilization are rapidly spreading to every corner of the globe. 

The real reason for this epidemic of ill health is both blazingly obvious and frustratingly nebulous; it appears anywhere the modern food system goes. Whether it’s an arctic population eating mostly seal meat and caribou or a southern population subsisting on rice and fish, once packaged food shows up, sickness does too. It is a shockingly consistent pattern. The cause is not a macronutrient or a micronutrient. It is not an excess or an absence of meat or grains or vegetables. The determining factor is the broad availability of Ultra Processed Food, or UPF.

I have long thought this to be the case with some caveats, but reading the book Ultra Processed People by the british doctor and author Chris Van Tulleken has both refined my views and raised interesting questions about what, if anything, can be done. 

The first problem in thinking about UPF is that determining exactly what qualifies can be hard. Here’s a short definition:

A practical way to identify an ultra-processed product is to check to see if its list of ingredients contains at least one item characteristic of the NOVA ultra-processed food group, which is to say, either food substances never or rarely used in kitchens (such as high-fructose corn syrup, hydrogenated or interesterified oils, and hydrolysed proteins), or classes of additives designed to make the final product palatable or more appealing (such as flavours, flavour enhancers, colours, emulsifiers, emulsifying salts, sweeteners, thickeners, and anti-foaming, bulking, carbonating, foaming, gelling and glazing agents).

Like I said, that’s the short version. For the complete picture you can read the whole paper here, but I think I can summarize. Put plainly, the idea is that the way food is made, marketed and consumed dysregulates our patterns of consumption. Breaking down substances into isolated components, reconstituting them along with additives and flavorings, testing and retesting these novel foods for maximum palatability, then making them widely available for very cheap with extensive advertising ensures that maybe not every individual will struggle to eat healthily, but that the population as a whole emphatically will.

Again, this is frustrating. While a product like Fruit Loops is obviously ultra-processed, there are a bunch of probably benign foods that also meet the strict definition (is it really so bad if your canned beans contain little citric acid?) and an increasing number of prepackaged foods that have ten or twenty ingredients, all of which theoretically might be in a kitchen, but which combine to make something that tastes quite a lot like a Dorito. The second issue is the lack of a clear mechanism. Is the problem the emulsifiers or the preservatives, the advertising or the availability, the caloric density or the flavorings? 

One of Van Tulleken’s strongest points is that neither of these particularly matter. More clearly delineating UPF would be useful, and why it deranges eating patterns warrants further study, but the important thing is that it derange them everywhere it goes. Diets focused on fat propose that its caloric density — nine per gram instead of the four found in carbs or protein — explain why we overconsume it. Diets that demonize carbs are more sophisticated, but still look to the interplay of blood sugar, insulin, fat accumulation, and energy to explain what’s going on. Both are easy to understand and the second is reasonably elegant, but neither explain much. UPF is a category that gets blurry at times and that proposes no particular causal mechanism, but it also does a better job of describing observable reality than other diagnoses.

Focusing on edge cases, ignoring the forest to debate whether the one particular trunk of wood rooted in the ground but lacking leaves and branches is a tree or a telephone pole, distracts from this critical fact. The observation that the diseases of civilization following close on the heels of ultra-processed food is so much more persuasive than any other account that it should be the default view until and unless someone can propose a better alternative.

This, unfortunately, is where things get a bit dark. Encouraging the public to recognize the problem with UPF has no obvious constituency, in part because this recognition indicts the foundation of the entire food industry. If the problem is the absence of a nutrient, Kraft can add fiber or vitamin D to its instant macaroni. If the problem is a particular additive, that also doesn’t matter too much. Campbell’s can remove BPA from its soup and McDonald’s can stop using transfats. But it is not a single additive or ingredient, it is methods that define UPF, and these methods — all that breaking down and reassembling of starches and fats and proteins, all that emulsifying and flavoring — are the reason food companies exist. Without UPF Kraft and Campbell’s and McDonald’s have no reason to exist.

Removing UPF from our diet would remove virtually every name brand from our pantries and fridges. Revolving doors shuttle people between the USDA, agribusiness, the FDA, and food processing conglomerates, which I’m confident means there isn’t a particularly strong interest within government agitating against UPF. I don’t think its a conspiracy so much as the very human impulse to not recognize an existentially threatening truth.

But a still larger problem is that even if experts and regulators saw the light, it’s not at all clear what would happen next. People like ultra-processed food because it is delicious, cheap, and convenient. When most of us think of the long term, we want to eat the foods that will promote health, probably as a family gathered around a table. But when faced with the reality of needing to get a meal made in half an hour after a long day of work, Doordash or a frozen pizza becomes a completely reasonable choice.

Even if there was an appetite for regulation, this is an area where the slipperiness of its definition makes it impossible. In his book Van Tulleken writes about several schemes in the U.K. to more heavily tax certain combinations of fat, salt, and sugar, efforts which lead to lots of litigation and lots of foods that get as close to the line as possible without crossing it, and which does not seem to have done a great deal for public health. The far more complex process of trying to adjudicate the status of the tens of thousands of additives that go into UPF would be an impossible task, one that would erect barriers the food companies would almost certainly find ways around in no time.

As much as ultra-processed food is a global health crisis, I am not expecting a global response, or at least not one beyond a new class of drugs that will hopefully help a lot of us eat less of the stuff. For the foreseeable future reducing the UPF in our diets is something we have to do individually, and what  that involves is the subject of next week’s post.