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Late last year, the health-care start-up Viome raised $15 million in venture-capital funding for at-home fecal test kits. You send in a very small package of your own poop, and the company tells you what’s happening in your gut so that you can recalibrate your diet to, among other things, lose weight and keep it off. In the company’s words, subscribers get the opportunity to explore and improve their own microbiome: Viome “uses state-of-the-art proprietary technology” to create “unique molecular profiles” for those who purchase and submit a kit.

This language says a lot about how Viome and an ever-increasing number of new health companies are encouraging people to think and talk about nutrition: as a problem of personal technology, where losing weight isn’t an experience of self-deprivation, but one of optimization, not unlike increasing a year-old iPhone’s battery life or building a car that runs without gas.

Viome and other start-ups in its market don’t characterize themselves as diet companies, but weight and other nutrition-adjacent health concerns are the chief things around which many of them are oriented. 23andMe wants to help you eat and exercise according to your genetics. Bulletproof wants you to change your morning coffee routine to increase your work performance and reduce hunger. Habit promises to study your personal biomarkers to tailor a nutrition plan just for you. Need a few hours of supposedly superhuman mental acuity and calorie burning? Pound a ketone cocktail and keep it moving. Can you control your body’s need for fuel through “intermittent fasting”? There’s an app for that.

Silicon Valley, not content with external devices, has pivoted to the self as its next great frontier. And in order for its vision of your body to take hold, it needs you to speak its language. Dieting is no longer a necessary problem of vanity, as it has been historically termed, but a problem of knowledge and efficiency—a rhetorical shift with broad implications for how people think of themselves. Where bodies might have previously been idealized as personal temples, they’re now just another device to be managed, and one whose use people are expected to master. We’re optimizing our performances instead of watching our figure, biohacking our personal ecosystem instead of eating salads.

In one way or another, all of these new services generally boil down to elaborate, expensive instructions to eat more of one thing and less of another, or to make a dietary addition or replacement that will unlock your body’s true potential. Convincing consumers that this new wave of diets is somehow distinct from the diet industry’s long, pseudoscientific history is a big task, but a potentially profitable one. According to the market-research firm Marketdata, the U.S. diet industry was worth an estimated $66 billion in 2017, but the number of active dieters in the country was down 10 percent. The firm found that that was due to two things: the growing popularity of the size-acceptance movement, and dieter fatigue. For new companies, laundering what are often fairly conventional diet practices through the language of technology provides the imprimatur of newness in the eyes of seasoned dieters, as well as a Trojan horse to reach consumers who, for whatever reason, were never interested in dieting qua dieting.

Many people who fall into the latter group are men. The diet industry’s modern history in America is feminized, which until recently left men as a relatively untapped potential market. “Gender contamination,” as the Harvard researcher Jill Avery coined it, is when a product or idea becomes so female-coded that men are no longer willing to engage with it. The classic example of this phenomenon is diet soda, and it’s no coincidence that gender contamination shows up most recognizably in the things people eat: The diet industry has always found its easiest prey among women, who are culturally primed to hone their appearance toward impossible ideals to demonstrate their social worth.

In a 2015 study, the University of Manitoba researcher Luke Zhu found that gendered food stereotyping was so profound that in order to make healthy foods seem masculine, marketers had to go so far as to invoke hypermasculine ideas like performance enhancement, which is exactly what diet-tech companies do. And on top of that emphasis, tech itself is already culturally coded as a masculine arena. So if we’re no longer dieting and instead biohacking in order to fine-tune our personal microbiome using state-of-the-art testing and results-based methodology, then the potential market broadens.

When people refer to tech companies’ largely dietary programs as “dieting,” the reactions of the company’s CEOs can border on personal offense. Losing weight isn’t the goal; they want to be their best on every plane of existence. “I’m focused on longevity and cognitive performance,” Geoff Woo, the CEO of the biohacking start-up HVMN, told The Guardian last year. It just so happens that being thin and physically normative always seems to get included as a fundamental part of a person’s “best.”

There’s some temptation to see an odd sort of gender parity in tech’s talk of the universalization of dieting norms: Maybe if we all feel the same pressures to pursue the same kind of perfection, then we’ve taken a step toward relieving those pressures uniquely harming women. But there may be something more harmful afoot, whether the people making these products realize it or not. Language creates a shared set of expectations and understandings. It’s not just products that are bought and sold, but also the ideas that underpin them. If tech CEOs define what counts as an ideal body—if they get to decide what optimization looks like for a human, and then put their considerable resources behind normalizing that definition and selling products meant to help people achieve it—then the real-world consequences for actual humans could go far beyond a simple linguistic shift.

People who are fat, for example, already experience multiple types of social discrimination: A 2016 study found that they’re less likely to be hired at a new job than similarly qualified thin people, and their weight means they’re more likely to be turned away from seeking important medical care. Losing weight requires physical and emotional difficulty and self-denial, and there’s mounting scientific evidence that losing a meaningful amount of weight and keeping it off is physically impossible for the vast majority of people considered medically overweight or obese. If people internalize the idea that changing your body should be as simple and necessary as cleaning up old files on your laptop, then the stakes for those who don’t or can’t do it could easily become even more severe.

There’s also the problem of another phenomenon that’s largely feminized in American culture, along with dieting: eating disorders. The deadliest one, anorexia, often involves fastidious attention to detail when it comes to calories and macronutrients, as well as massively restricted opportunities to eat. Intermittent fasting, meal replacements, and ultra-detailed diet plans might not always be symptoms of disordered eating unto themselves, but a veneer of safety from scientific language can obscure the tendency for those behaviors to become physically harmful, and it can make intervention more difficult for family and friends.

On its website, as part of its marketing materials, Viome asks, “What if illness could be elective?” The query seems to be intended as hopeful, but for those who live with anything culturally coded as an illness or disability, it could be chilling. If illness could become something that can reasonably be circumvented by some people, it’s unclear what would happen to those without the means to avoid it. Viome’s CEO, Naveen Jain, says his company has considered the price, and that he hopes the free market will soon make the company’s services more affordable. Viome’s RNA sequencing, for example, used to cost $10,000. “We know that once something is on an exponential curve, costs will come down so everyone can afford it,” he told me over the phone. “My hope is that in six months, it will cost less than $100.”

What’s unclear is what would become of people who lack the desire to self-optimize according to Silicon Valley standards. In the tech vocabulary of dieting, there’s little space for deviation based on pleasure or personal preference, let alone on differing ideas of what actually constitutes a flaw in need of fixing. Most people running these companies seem sincere in their desire to improve people’s lives, and in the cases with real scientific advances at play, their methods may pan out in some ways. Viome’s technology really does seem like an opportunity to identify sub-allergic food sensitivities in those with the means to try it, and the microbiome is a fascinating and fertile ground for further research. Across the past few years, we have seen several American tech companies fail to anticipate how their good intentions might go bad, and once a product is popular and profitable, there’s not much incentive for executives to rein it in.

Science has already made relatively clear that healthy diets involve eating a diverse, primarily plant-based diet of fresh foods over the course of one’s life. The straightforwardness of that advice doesn’t make for great product marketability, but it does take into account something that the language of technology may obscure about nutrition: There are plenty of ways to be a person. Jain was careful to tell me that Viome doesn’t want to conflate thinness with health, although it does list obesity and related conditions among the things its diets intend to treat. That line is something all of these start-ups seek to walk. But what people need most might not be more products to make them perfect, but a broader idea of what perfection means.

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