Letters to My Great Grandchildren, Part 1: Obesity and Bewilderment

Let me begin with the obvious. I do not actually expect you to actually read these. The dead, as Kipling observed, are only borne in mind for a little, little span. Digital preservation being what it is right now, I don't even really expect it to survive. And even if you do somehow read it, it is hard to know what will strike you as interesting about my time. Assuredly, the things that I find noteworthy about modernity may have nothing to do with what interests you. A lot of your questions will probably relate to things like "what was life like without [indispensable invention X]?". Alas, I cannot tell you - it seems pretty normal to me! One throws this note in a bottle into the digital sea - the modern version of the same impulse that made men once paint on cave walls.

One thing I can tell you, however. In certain respects, the early 21st century is a bewildering time to be alive. And this is especially so in a respect that I imagine will strike you as especially jarring when you look at photos from this time. Namely, why is everybody so enormously fat and unhealthy-looking? 

The immediate question you are probably wondering is how we didn't figure this out. Didn't they look around and notice there was a huge problem? How could you possibly fail to spot the obvious answer of [cause Y]? 

To take the obvious first - we definitely noticed. Human nature did not change so much that the obese failed to observe that they were obese. Nor did they fail to observe the health and lifestyle costs. Indeed, in the sexual marketplace, the fewer people who are thin and in shape, the higher the payoffs to those traits, making the perception even more acute. 

It is glaringly obvious that, at least in this respect, something has gone very wrong with modernity in the last 60 years or so. Obesity, testosterone, sperm counts, the list is long. But time series changes are incredibly difficult things to parse out. The problem is that dozens, if not hundreds, of things are changing all at once. The curse of knowledge is always a tough one to circumvent. When you know something, it will always seem like it ought to be obvious to people who don't know that thing. But it isn't. It turns out it is more difficult than you think to credibly put yourself in the shoes of someone who doesn't know, in this case, why everyone got so fat.

To begin with one aspect that makes the problem hard. Across different categories, there is a large difference in regulation about what can occur, and how much data collection and notification goes into it. To take one example, which may or may not be relevant to obesity (which is the most glaring and acute of the modern problems). There are a lot of requirements about labeling the ingredients in food. But there are almost none about labeling the chemicals used the packaging that the food comes in. There is some attention paid to the composition of trace chemicals in the water people drink, but it depends a lot on which chemical. There is little attention paid to the amount and type of radiation people are exposed to. Lack of regulation and lack of interest is strongly correlated with lack of data to test hypotheses well. The hardest of which is not "does this increase weight in controlled settings", but "does this quantitatively explain the world around us?" 

Are any of the examples above actually *important*? That, future reader, is the aspect I most want to discuss. The problem is not the lack of plausible theories, or possible contributing causes, or partial remedies. The problem is the complete surplus of them, and the difficulty of sifting between them. Smart, motivated, curious people live in a world of leaping from one lead to the next. They have a scarce budget of time and attention and effort, but great confusion as to where to allocate it to solve a problem that seems all pervasive. The obvious candidates are things associated with modernity, broadly defined. But which ones? Do you need to be reducing the amount of carbs you eat? Do you need to cut back on seed oils? Less salt? Do you need to limit the hours in a day when you eat? Or perhaps the problem is chemical in nature. Do we need to work to reduce our exposure to  polyfluoroalkyl substances? BPA? Microplastics? Lithium? Antibiotics? Glyphosate? Blue light? 5G radiation?

Or is the problem even thornier - that we were simply evolved for a world of calorie scarcity, and our hardwired instincts are now pathological in a world of permanent calorie excess, moths circling a flame of our own making, consisting of hamburgers and doritos? Because, as Eliezer Yudkowsky put it, we can do what we want, but we cannot want what we want? It is striking that the unusual period in history when we consume too many calories is the same period, and same places, that our houses now routinely accumulate junk possessions which occupy much time and effort getting rid of. Both problems would seem bizarre to people a hundred years ago. 

I have no doubt this list will seem comical and insane by the time you read it. But this is the point. To live in 2024, and spend any time pondering not just obesity, but the various other maladies that seem to afflicted us more than in the past, is to have a complicated and uneasy relationship with the modern world. There are many things that are probably in the category that the distribution of effect sizes starts at zero, and includes small negatives and considerable negatives. That is to say, not many people seem to think you should be *increasing* your consumption of microplastics. But is it a small problem, or a large one, or actually not really a big deal? That's the difficulty. You can try to play it safe, as it were. But the precautionary principle breaks down very fast when the space of possible things to avoid is sufficiently large. And many of them carry tradeoffs that only become obvious in hindsight, because some of the things are so prevalent. You might be worried about contaminants in your water, perhaps. So you buy a cheap water filter, except now all your water runs through a plastic container made of whatever as-bad-or-worse BPA substitute they're using these days. You take supplements to try to improve your health. But you buy the easy to swallow ones without thinking about it, and end up consuming a lot of whatever is included in the dubious term "gel caps". One ends up being pushed towards rejecting more and more of the modern world, where the end point is rejecting it wholesale, like the Unabomber, or the Amish, or Boko Haram. We don't want this, of course. We still want to be able to write our essays on the internet. 

You can guess at the outlines, of course. It has to be pervasive, hard to avoid entirely. Every area of every country seems to have gotten fatter. It has to be associated with modernity, probably the 1960s/70s onwards, but also increasing over that time. In the cross section, who is affected more seems to be largely genetic, from the twin studies. But since genes haven't changed much in 70 years, this means either genes are a big determinant of response to a time series change, or genes determine willpower, and the ability to use effort to overcome the force pushing you in the same direction. It doesn't seem to be from cross-sectional environmental exposure. Which is weird, since a large time series change sounds a lot like environment. 

You're probably thinking to yourself, that's it? Well, not exactly. There is lots more specific evidence, but this is much more murky and open to interpretation. If you want to know how to control obesity, you've got a larger set of options, with their own limited success. But, for instance, it seems very unlikely that the rise of obesity in the 1980s came from people abandoning their previous one-meal-a-day keto diet, even if you think that might be a decent remedy for the underlying cause. If people stick to it. The distinction between "this would work, if people actually do it", and "this is a thing that the average person could credibly do" is also surprising blurry in the way matters are discussed. 

The other aspect, which you might not guess, is what the response is to this confusion. You would probably guess at there being a frank acknowledgement of the lack of understanding. But there's not. There appears to be some strange aspect where in the face of intractible problems, people would rather believe vehemently in some theory or other, and that it just hasn't been tried hard enough. People would rather hear a wrong theory, vigorously and persuasively espoused, than to frankly admit that all their theories aren't working, and they're largely out of ideas until big pharma invents the right drug. There is a need for action, even partial or unsatisfactory or pointless or symbolic or improbable-to-be-successful action. And once this has occurred, cognitive dissonance takes care of a lot of the rest, changing beliefs to match the actions already taken. 

People believe passionately in their particular theory of weight loss and weight gain. Their passion is strangely out of all proportion with the actual level of confidence that you could attach to intent to treat estimates. That is, if you think the problem is seed oils, is this the same as making a concrete prediction that everyone who cuts seed oils from their diet by, say, 90%, and makes no other changes, will obtain and maintain a healthy BMI? I mean, it would probably help, at least a little. But that's not the same thing. Notably, they believe this much more passionately than for things where knowledge is straightforward. Nobody is passionate about vitamin C being a cure for scurvy. Hell, nobody is even especially passionate about whether Ozempic tends to produce weight loss, because it does. This is just boring, ordinary knowledge. But why everyone got fat in the first place? The honest assessment, that we just don't really know, is the one you are perhaps least likely to hear. 

So here we are. In these strange times, to admit to this plight, is to have some sympathy for the Carthaginians. Nature abhors a causality vacuum. It is more comforting to sacrifice some children to the gods to try to bring rain, than it is to sit there powerless, day after day, not doing anything, not able to even really know what you should be doing. 

For now, Ozempic has been a small light at the end of the tunnel. Once better drugs get invented, and it perhaps gets fully solved, it might eventually just be a subject of later academic or historical interest as to what it was all about in the first place, rather like what caused the decline of the Roman empire. In the shorter term, if we do find out the answer, the people so strongly clinging to this or that theory of diet will forget that they ever did so. Cognitive dissonance is strange like that.

In other words, your likely bewilderment looking at photos and videos of us is matched only by our own bewilderment in looking at ourselves. It is a strange time, but alas, we have no other. 

Anyway, I hope to write some more of these soon. Life is busy, not least from looking after your grandparent and great uncle or aunt. 

With all my love, 

[Shylock]