Consequently, hosting a lavish banquet or ordering lobster is no longer a sufficient signifier of status; today, a sign of true wealth is the ability to forgo food entirely. Eating essentially betrays a person’s most basic human needs; in an era obsessed with ‘self-optimisation’, not eating suggests that a person is somehow ‘beyond’ needs and has achieved total mastery of their body with a heightened capacity for efficiency and focus.
“There is a history in Judeo-Christian societies – and likely in many other religions, hence the widespread practice of fasting – where demonstrating a lack of need for material things, especially food, and being able to demonstrate self-control and discipline are signs of spiritual transcendence,” Dr Woolhouse says. Famously, Italian saint Catherine of Siena would fast for prolonged periods of time as a means of demonstrating her devotion to God through extreme self-control. “But there’s also a class dimension to this,” Dr Woolhouse continues, “because being able to demonstrate a lack of need for material goods, like food, suggests social transcendence too; it’s symbolic of living a life whereby our material needs aren’t a daily concern.” She adds that “fad diets are very unlikely to take off in societies where there are food shortages or food insecurity.”
It’s still jarring to watch celebrities openly admit to fasting for 23 hours a day or taking 14 different supplement pills in lieu of a balanced breakfast. “It normalises and sanctions practises that in other contexts would be regarded as eating disordered,” Dr Woolhouse says. “When eating practices are packaged as ‘done in the name of health’, they are more socially acceptable and difficult to contest.” She points out that a normal teenage girl restricting her diet in the same way as Johnson would likely be regarded as ill and in need of medical intervention. “What we, as a society, regard as ‘normal’ and ‘abnormal’ eating is contextual and largely rides on how those eating practices are framed.”
It’s obvious but bears reiterating that extreme, fad diet trends are both ineffectual and dangerous. But this trend isn’t really about food or health. It’s about performance. It’s a way for the moneyed classes to signal their wealth and status and posture as above us mere mortals who debase ourselves by eating.
You're right that fasting is beneficial in part because it temporarily cuts off the intake all the poisonous shit in a typical diet, but there are all kinds of other very real physiological and evolutionary reasons that people feel better and get health benefits from fasting. It's something that has been well known and commonly reported since long before microplastics and all the other modern poisons we're exposed to. Fasting is one of those things you can find throughout history and in all sorts of different cultures as a remedy and spiritual practice... and has been confirmed by modern medicine.
Another thing to keep in mind is that fasting actually wouldn't help a person feel better with respect to a lot of those poisons which are more of a slow, long-term detriment, where briefly stopping their intake before starting again wouldn't change your immediate experience. Since you mentioned lead, if a person has been getting small amounts of lead over long periods of time, suddenly not getting any lead for a couple days isn't going to make them feel any better in large part because lead gets deposited in the bones and will keep poisoning someone even after they stop consuming it. Lead also causes at least some irreversible neuronal damage, especially to people exposed in childhood which makes it so fucking insidious and evil that our overlords intentionally continue to allow it to be a problem in poor and minority communities. Fasting isn't going to make those lead-poisoned kids or the adults they become suddenly feel less lead-poisoned. But it might make them feel better for other reasons.
Long reply incoming.
It's not universal, but it is broadly beneficial for most people, especially people with western diets. You can be skeptical of that, but it really is backed up by the science, with very clear physiological mechanisms explaining how and why it's beneficial. Anecdotally, almost everyone who gives it a try will also have positive things to say about it. Normally, I wouldn't really count that anecdotal thing in, but I'm not just talking about people trying new internet trends here, we're talking about something on a scale of (for example) hundreds of millions or more Muslims who do fasting as a spiritual practice and religious observance.
As far as coinciding with the tendencies you mentioned, once again... fasting is not some new fad. It may have gained some mainstream popularity (as it has in the past since fads are often cyclic) and is recently getting discussed in the same rounds along with actual fad diets, but like I mentioned before, fasting is something that almost every major religion has incorporated in some way. You talk about listening to our bodies and the folly of trying to repress our desires but a major, even basic part of listening to our bodies is learning how to balance our desires. I'd agree that there has been a puritanical current especially in American culture that demonizes natural and healthy desires resulting in their repression in deeply unhealthy ways. But that doesn't mean that overindulgence doesn't exist or that it isn't a major problem for a lot of people, or even that there isn't also a precedent for overindulgence on a cultural level as well, given the capitalist emphasis on consumerism. Despite the bourgeois shitheads in the OP article, it's no secret that traditionally the way to show off wealth has been through flaunting excess.
As with most things, there is a healthy balance that needs to be found between short term desires and long term health. I'd hope that isn't a controversial thing to say. The exact location of that balance varies with the individual, but to look at modern western diets along with all the severe health consequences they are known to be responsible for and conclude that the problem is the suppression of desire is just... well, misguided to put it lightly. Like we know the addictive nature of the processed sugars that are pumped into food for the express purpose of getting people to keep eating long after they've had even ten times the amount that would be healthy to have in a day. It isn't a person's fault for having the desire to eat more because it is literally a physiological addiction, that again, has been intentionally manufactured to drive consumption and therefore profits. But the immediate answer for someone suffering from that addiction is absolutely not to give in to the desire and just eat more. No more than the answer for someone with an opiate or alcohol addiction is to just indulge when the desire is felt, but rather to make an attempt to curb the consumption of opiates/alcohol/sugar despite the sometimes overwhelming desire to give into it. Listening to your body is much more about recognizing what it's telling you about its long-term well-being than it is about sating its immediate desires. And for the vast majority of people especially in the west/global north, fasting is a positive way to respond to the malaise their body is screaming at them with. Almost everyone who really tries fasting, including people in this thread, report that they feel much better as a result of doing so. That is listening to your body.
I'd take a look at that study then, but with an extremely skeptical eye, considering there have been literally scores of studies saying the exact opposite. Thee major lifestyle element that most strongly predicts longevity is restricted caloric intake. In other words, of all the factors that we have been able to find that correlate with people living longer lives, is people who have taken in fewer calories over their life. This is well known as any quick search can quickly confirm for you. As another obvious example, again, we know through countless studies with overwhelming evidence how bad a high intake of sugar is, how it directly leads to heart disease and of course diabetes. Diabetes (specifically type II), as you may know, is epidemic in the US. Diabetes essentially is insulin resistance, and the way to fix insulin resistance is to stop all consumption of sugars/carbohydrates for a time, ie, to fast. I'd recommend looking up "fasting + insulin resistance." This is all stuff well known to science and medicine, but there is so much more I could get into. Like what we now know about autophagy and how fasting massively speeds it up, the role of mTOR signaling pathway in fasting, or the evolutionary reasons that fasting is good for a species that through most of its existence experienced famines where it had to cope with surviving without food for lengths of time. (The "3 square meals a day" thing is a very recent phenomenon). I'd post links of the many many studies that back all this up if it's absolutely necessary, but it can all be easily confirmed with a web search. Whatever studies you're talking about, if they are as you say, are in complete contradiction of well-established consensus.
Fasting is not appropriate for everyone in every circumstance and I never implied otherwise. There are absolutely people who should not do long fasts, and though fewer, there are even people who shouldn't do intermittent fasting. Definitely. But they are in the minority. It's funny that you mention gut issues because one of the first and most successful methods for treating the most common gut issues (I know a number of people with colitis and IBS, the latter I used to have myself) is fasting and elimination diets. This is what gets recommended by doctors, and for good reason. I have no idea what your issues are, so I wouldn't presume to tell you that fasting would be the answer for you, but something to consider is that almost every treatment for an ailment will cause initial discomfort. For many people who experience that normal nausea upon forgoing food longer than they're used to, including me, it's because it's literally a type of withdrawal. Your body has adapted to having food at the frequent intervals we usually eat, particularly carbohydrates which can be quickly converted to energy. Fat can also be used as a source of energy but your body won't tap into that longer-term energy storage mechanism until the carbohydrates have been used up. If your body is not used to doing that, it will be uncomfortable. But so too is it uncomfortable for a brain used to a steady supply of external opioids to go without them until it adapts to using the endogenous ones again.
As for practicality, sure. That's a different issue. Fasting takes a commitment and very likely will include that initial discomfort. For people barely scraping by and having to work multiple jobs and keep their energy constantly up, taking the downtime that one would need for (as an example) a 3-day fast just isn't feasible. That said, if they had some respite for a while and some time to tend to their health, most of them would find that fasting would help them. The same way someone who needs coffee to function and go to work but gets no sleep would find that if they could quit caffeine and get better sleep, it would help them cope with work in the long term, but quitting coffee just isn't feasible in order to keep up with the necessary grind. On the other hand, someone who is in a relatively easy position to give up coffee and get better sleep would not be listening to their body or doing themselves any favors by using the excuse "ugh, I just feel like crap when I don't get my caffeine." I'm not implying that's you, but it definitely is some people who would pooh-pooh something genuinely positive because it seems uncomfortable at first.
It seems like rather black-and-white thinking to keep referring to it as being either a universally good practice or typical self-help-book bunkum. It is not universal. But to view it through the lens of being "minimalist" or worse, JP-esque self-help bullshit is a very narrow and inaccurate way to look at something that has such a long history, cultural significance, established medical use, and overwhelming scientific consensus.