“Cereals here in the United States contain a packaging ingredient called—God, I’m paranoid." The natural-food advocate Vani Hari paused, laughing, looking at a man standing a few feet from our table in a Union Square coffee shop. He was huddled over his phone, just waiting for his coffee—or so it seemed. She lowered her voice, continuing, barely audible: "... called BHT."

Hari looked in my blank eyes. I asked, "In the plastic bags?"

She nodded as if I'd just been let in on the secret to end all secrets. "And in the U.K., they can't use it," Hari, who is better known through her blogging, speaking, and TV appearances as "The Food Babe," continued. "The purpose of it is to leach into the cereal, so it keeps it fresh. And, how many millions of kids are eating this every single day?"

"Why did the U.K. take it out?" I asked.

"They don't allow it," Hari said.

"They must have a reason."

"There are studies that suggest it's linked to cancer, tumors," she said. "It's an endocrine-disrupting chemical."

Such is the gist of many of the food-additive campaigns that Hari has undertaken: A chemical in the U.S. food supply is not allowed in other countries, so why is it being used here? Petition the food companies to take it out. Over the past three years, Hari has rapidly become one of the most popular voices on nutrition in mainstream media. She has lived the American dream: monetizing a lifestyle blog and quitting her job to write about what she's eating and why.

Hari is now working on developing a TV show, and her first book, released yesterday, is bound to lead bestseller lists. The title, a mouthful, leaves little to the imagination: The Food Babe Way: Break Free from the Hidden Toxins in Your Food and Lose Weight, Look Years Younger, and Get Healthy in Just 21 Days! It is more than just another ultra-simple diet plan, or a compendium of claims intended to provoke, devoid of nuance, though it is also those things. ("Could an apple be more fattening than a hot fudge sundae? Quite possibly, especially if you consider the exposure and accumulation of pesticides over time in the body.")

The book also offers the origin story of The Food Babe—how she left her job as a financial consultant and, despite no training in human metabolism, toxicology, or environmental science, became an unintentionally influential figure in public health. The book does little to address that she has also drawn the ire of many scientists who believe her claims are inaccurate or even dangerous. But Vani Hari did not intend to attract attention on the scale that she has. Her crusade began simply enough, with her own health issues, and the recovery that ensued after she discovered an all-natural approach to life. "Everything I had been putting in my body," she writes in the book, "was either made from something out of a chemical factory, sprayed with chemicals, or genetically modified to make companies richer and me sicker."

Hari's secrecy when we met in New York was not because the story of butylated hydroxytoluene (BHT) was a particularly hot one. The additive has been widely used in cereal packaging for many years. BHT has to be listed as an ingredient on food labels, and some consumer-protection advocates like the Environmental Working Group have advised people to avoid it when possible. BHT is not a listed carcinogen by the International Agency for Research on Cancer, but at high levels of exposure, rats have been found to develop lung and liver tumors, as well as problems with motor skills. These issues have not proven themselves to be relevant to humans, so the Food and Drug Administration classifies the chemical "Generally Recognized as Safe."

Rather, Hari had explained that her secrecy was because, five days after we met, she was going to launch a campaign imploring her legion of followers (dubbed "The Food Babe Army") to demand that General Mills and Kellogg's stop using BHT. She made me swear that I wouldn't break the news in advance. I swore. And five days later, Hari posted a petition on her widely read blog FoodBabe.com, and pushed it to her 900,000-plus Facebook followers. Within a few hours, the petition had garnered more than 17,000 signatures. By the end of the day, last Thursday, Hari had published a press release saying that General Mills and Kellogg's had announced that they were going to phase out BHT.

She called it "a giant victory for the Food Babe Army." (General Mills' brand manager said the company was "already well down the path of removing [BHT]," and that the petition played no role in that.) In either case, this is far from the first victory to Hari's name. Since 2012, she has been leading campaigns demanding that food manufacturers remove ingredients that concern her, however remote the odds of serious danger. In March 2013, she successfully implored Kraft to remove one of the chemical dyes that gave its macaroni and cheese that classic yellow-orange glow—because, Hari writes in the book, "at least one study" suggested a correlation between the chemical (yellow 5) and hyperactive behavior. Before that, her blogging and advocacy led to changes by Chipotle and Chick-fil-A, among others.

"I never gave permission for my body to be used as a toxic-waste dump or a science experiment," Hari writes in the book, blaming the food industry for said use. "You’d think our Food and Drug Administration (FDA) would protect us from all of this, wouldn’t you? Hell, no. They’re part of the problem." Her stance on food additives is an absolute one: "There is just no acceptable level of any chemical to ingest, ever."

Toxicologists the world over dispute that with the fundamental adage "The dose makes the poison." Any substance is toxic at high enough quantities. Even something as banal as carbon dioxide can asphyxiate a person. And, similarly, almost anything is benign at low enough quantities. These are things that Hari knows but gives little due, sticking instead to the messages that are most visceral. She escalates the concerns raised by possible associations to concrete, actionable fear. Chapter One, titled "You've Been Duped," sums up the most divisive elements of her ideology:

Every bite of food that passes through our lips, and every glass of water we drink, are potential sources of toxic chemicals, including pesticide residue, preservatives, artificial flavors and colorings, addicting sugars and fats, genetically modified organisms, and more. These toxins can travel to, and settle into, all the organs of your body, particularly the liver, kidneys, gastrointestinal tract, and lungs—and do great damage. Scientists are now blaming chemical-ridden food for the dramatic rise in obesity, heart disease, chronic fatigue syndrome, infertility, dementia, mental illness, and more.

Most of the scientists who have spoken on Hari's work, though, are less than supportive of that sweeping message. Rather, her work has drawn ardent criticism, primarily from a vocal contingent of academic researchers and doctors, who accuse her, in no uncertain terms, of fear-mongering and profiteering. They say that she invokes science when it is convenient, as in the passage above, but demonizes it when it is not—as in her blanket case against any and all genetically modified food. Last month, NPR ran a critique of Hari's work, quoting several of her outspoken detractors. Science writer Kavin Senapathy, for one, captured the concerns of many in saying that Hari "exploits the scientific ignorance of her followers." Others, including neurologist Steven Novella, have said that she is to food what Jenny McCarthy is to vaccines.

"The Web is cluttered with people who really have no idea what they are talking about giving advice as if it were authoritative," Novella wrote in a blog post. "Often that advice is colored by either an ideological or commercial interest. The Food Babe is now the poster child for this phenomenon." NPR also quoted oncologist David Gorski, who has called Hari "a seemingly-never-ending font of misinformation and fear-mongering about food ingredients, particularly any ingredient with a scary, 'chemically'-sounding name."

In recent months the attacks have escalated, and Hari has mobilized her army for war. Her response to many detractors is a simple and effective charge of corruption: Those who criticize her work are doing so because of ties to the food industry. Rebutting the NPR article, Hari addressed her followers with an impassioned response, opening with a quote she attributes to Mahatma Gandhi: "First they ignore you, then they laugh at you, then they fight you, then you win." (If the Gandhi invocation feels a little self-aggrandizing, compare it to the book's forward, in which 10-Day Detox Diet author Mark Hyman likens Hari's work to that of Martin Luther King, Jr.) That was followed by more than 5,000 words of responses to her critics, including some humility—"I’ll admit it. My microwave blog post was not my most impressive piece of work"—all the while imploring her army to stand by her side in these trying times.

Illustrating the depth of what Hari endures, the post also includes images of some of the most hateful vitriol she has received from various dark corners of social media, complete with threats of rape and entreaties to kill herself.

"I'm getting attacked every day with a death threat," she told me. When it first started, the criticism and negativity dissuaded her in her work. Now, she explained, it fuels her. It is becoming part of her identity as a crusader. She implores her followers to join the battle, to resist the influence of the food-industry-fueled opposition.

Lauren Giordano

Hari is a paragon of opportunism in that way, turning criticism in her favor, incorporating it as part of her outsider identity. Her critics are part of an establishment trying to suppress the truths she holds, the truths they don't want you to hear. This week, Hari braced her fans on Facebook for the release of her book: "The ‪#‎FoodBabeWay‬ is hitting stores everywhere on Tuesday and I'm scared to death. The Food Industry is not going to be happy, they are going to fight back with their detractors leaving dishonest reviews and try to take me down any chance they get. ... " The post generated more than 9,000 likes. In the same way, she opens the book by turning her lack of scientific training into a point in her favor: The establishment is the problem, and she is its antithesis. She is at once the victim and the hero.

"What's really concerning to me is that the majority of the medical establishment, including registered dietitians, have some sort of industry tie," she told me. "It's entrenched. Sometimes it takes an outsider to see the corruption. And to talk about it in a way that people understand."

I asked her about that positioning, as the relatable underdog-outsider going against the medically trained elitists. "It wasn't intentional," she said. "This just isn't stuff that you have to be a doctor or scientist to understand, and the fact that they're telling you that, there's a problem with that. That you have to be a food scientist in order to understand what these chemicals do in your body. Not really."

Nutrition and human metabolism are among the most complex and consequential disciplines in the health sciences, but sentiment like Hari's is not at all rare, evidenced by the many celebrities who feel qualified to write their own weight-loss books. They sell well, at least in part because people who are not scientists tend to be better at using evocative language and less married to conservative "may be related to"-type caveats; the scientific establishment that guardedly posits potential correlations, and ends every statement with "more studies are needed." The deferential language of careful science, unfortunately, lends itself to little influence on the emotion-laden mainstream Internet.

Back in 2011, a public-health program at the University of California, Berkeley advised consumers about the cereal-bag chemical: "The nutritional benefits of, say, a whole­ grain cereal with the additives outweigh any risk. But because [BHT's] health effects are still unclear, limit how much you consume." Alas, the staid article did not lead to the removal of these chemicals from the food supply. That's where one needs a Food Babe.

Hari is also part of an ongoing, escalating challenge to the identities of academics as gatekeepers of knowledge. The role of celebrity in giving public-health advice is not unique to the Internet era; Jane Fonda was the fitness expert of a VHS generation. But the idea of a lone consultant becoming, in three short years, more influential than entire university departments of Ph.D.s, is indicative of a new level of potential for celebrity in health messaging.

"I wanted the hashtag to be #CerealKiller, but people talked me out of that," Hari said, laughing but not unserious. I told her, as a writer who not-infrequently covers food and nutrition, that I worry about making people freak out when they shouldn't. Toxic contamination of the food supply is an incendiary topic, and telling people they've been poisoning themselves or their kids (however innocently) can be a serious burden.

"And that's the problem that we have: too many moderate people," she said. "We need someone demanding change."

NPR posited that its readers cannot simply ignore Hari, because her reach is growing. She wrote an op-ed about her success, and the widespread misuse of the term natural, for The New York Times. Hari is on track to become the next Dr. Oz-level health-media personality. She has already been a guest on the embattled doctor's daytime-television extravaganza, during the macaroni-and-cheese crusades. By the end of the campaign, the petition to remove yellow 5 had almost 250,000 signatures. She's clearly speaking to people in a way that resonates. Analytically-minded people, her scientist critics among them, often with big health ideas of their own, might do well to understand why and how these messages work. Or, as Hari phrases it, as a challenge: "People chastise me for being too simplistic, but it's like, okay, how are you getting through to people?"

* * *

At the heart of her superhero-style name, The Food Babe has a superhero-style origin story. It's the archetypal one of a reluctant rise from humble beginnings; one that involves a transformation, a time at rock bottom, and a rise to fight a clear-cut battle of good versus evil.

One cold winter night, when she was in her early 20s, Vani Hari developed some pain in her lower abdomen. She went to a nearby hospital in Charlotte, North Carolina, where she was born and had returned to live after college. In the emergency department, she remembers being told to relax, that her ovaries were "moving," and she'd be fine. The next morning she went in for a second opinion, and she was diagnosed with appendicitis. Within an hour she was having her appendix laparoscopically excised. Recovering in the hospital that night, she remembers someone took a picture of her, and she ripped it up thinking she looked "so, so bad." And she definitely felt horrible.

Since graduating from college, Hari had been working as a consultant at Accenture. She kept long, exhausting hours. She recalls being afraid to leave to use the bathroom during meetings because the environment was so intense. She ate decadent catered meals from exorbitant expense accounts. "A bunch of stuff that really doesn't serve the body," she recalls. "But I wanted to fit in, I wanted to be a partner. I was ambitious." But the health issues she'd had as a child—allergies, eczema, asthma—flared up. Over the first year of the job, she gained between 30 and 40 pounds. She felt bad and "didn't look that great."

When the appendicitis hit, that was a breaking point. Lying in her hospital bed, Hari said, "I just had this light bulb awakening moment, you know? This isn't how I want to live."

She resolved to pay better attention to her health, and to figure out exactly what foods would best serve her in that. "I avoided processed foods like the poison they are," she recounts in the book. "I fed my body fresh organic foods—fruits, veggies, grains, good fats, and other whole foods—and made time to nourish my body back to health." Her eczema vanished, as did her asthma, anxiety, and gastric issues. "I got back to an attractive, normal weight, and I’ve stayed there," she recalls, "even by eating 1,800 calories a day, normally a lot for a woman with my frame." And, a message not to be taken as advice to readers, she eventually stopped taking any and all medications, prescription and over-the-counter.

She still stuck with the consulting job for a while, because she says she was raised not to quit. And she was raised a competitor. As a top-tier debater in high school, Hari was a state champion. Even as her grades suffered from her devotion to the debate team, she was still recruited to colleges because of her skill. "It was actually the funnest time of my life, until now," she recalls.

"What made you excel?"

"I love competition," she said. I laughed. She didn't. "I love competition. I love competition of ideas. There's something really gratifying about convincing someone of something. It's probably born into me. And there are so many parallels between what I was doing back then, and what I'm doing now. In that it's competition, and being the underdog, and convincing people that they need to think about healthier eating, drop the processed food, this food is killing you."

She started putting those ideas in writing in 2011. Not wanting to mix her Internet identity with her day job as a consultant, she initially went only by the name The Food Babe. For the first year and half of her blog's existence—which today features an actual photo of Hari examining a nutrition label with a magnifying glass (as does the cover of her book)—the top of the page was illustrated with cartoon characters. One was a woman lifting weights in a bikini. "It was a cartoon, though," Hari said. "It wasn't graphic. But, it was a babe."

Sexuality is an element of health, I said.

"Well, I'm just saying it wasn't, like, graphic."

Her personal brand is always family-friendly, in the traditional sense. She says the "babe" branding—an interesting approach in a scientific arena notoriously dismissive of female voices—was never her idea. When she asked her tech-savvy husband to procure a domain name for her blog, as she recalls, EatHealthierForever.com was taken. So he suggested FoodBabe.com, which was somehow available for $10.

"At first I was like, I'm not calling myself 'The Food Babe,' that's ridiculous," Hari said. "But then I thought, well, why don't I teach everyone to become a food babe?"

In its early days, FoodBabe.com was essentially Hari's aspirational lifestyle blog, divided into three categories. In one, she wrote about workouts. In another she wrote about food. And in the third she recounted her travels. She is, she admits, obsessed with travel.

"I didn't start the blog to take on the industry," Hari said. "I had no idea that this would start to happen. I had no idea that a blog post, something I wrote, would change a company. But when that started to happen, that's when I knew I had to quit my job, that I had this gift that I need to share with the world."

Feeling that she owed it to herself, to her mother-in-law who had recently died from cancer, and to her father who had recently been diagnosed with cancer, to spread her message of health through natural food, she gave up television for Lent (she's not Catholic, but, still) and found time to start blogging after work.

"People ask me, how did you figure out how to write?" she recalls. "I had no copywriting training or anything like that. I put myself in my own shoes as a normal person and thought, what would I want to read? What headline would I click on?"

And there she found an uncanny ability. Her post titled "If You've Ever Eaten Pizza Before, This Will Blow Your Mind (Maybe Literally)," in which she lists which name-brand pizzas contain MSG and GMOs (or "possible GMOs") is a triumph of click-generating headline writing. It has been shared on Facebook 384,000 times. With that acumen, and multiple similar posts before it spreading across the Internet organically, as from concerned pizza consumer to concerned pizza consumer, it was a matter of only a short while before Hari had a sizable readership. But it was the Subway campaign, really, that brought The Food Babe into the national spotlight.

* * *

In 2013, Hari filmed herself eating a yoga mat, as she writes in the book, "to drive the point home." The point was that azodicarbonamide, a chemical used in commercial bread production, was the same one used in yoga mats. Hari targeted Subway bread specifically, and implored her Army to "eat fresh—not yoga mats." Within a year after her post, multiple national news-media outlets having picked up the story, Subway agreed to stop using azodicarbonamide. As she was sitting on her couch in Charlotte watching television with her husband, she recalls, a Subway commercial came on, and there was a little asterisk that said "no azodicarbonamide." They gave each other a high five.

"Bread is a foam. Even culinary experts will tell you," argues Kevin Folta, professor and chairman of the department of horticultural sciences at the University of Florida, and one of Hari's most outspoken critics. And azodicarbonamide is used as an agent to maintain the structure of foams. So, what's the problem? Folta considers azodicarbonamide nothing more than a digestible organic molecule, and one that helps bakery products maintain uniformity and structure over time.

"It was a perfectly safe food additive for years," Folta told me, "until she came along and decided that Subway bread was essentially a yoga mat."

The Subway campaign was the first that drew Folta into following Hari's work, with increasing fascination over, as he put it, "the fact that she is able to mobilize this army of blind followers who reject science and follow her words, to smear and harm the reputations of companies that are doing nothing wrong."

Folta is among the scientists who, especially in recent months, have devoted substantial energy to discrediting Hari—or at least, reorienting her. He recently tweeted a photo of her holding an issue of the journal Nature Genetics that included a report on the sequencing of a strawberry genome, writing, in parody of her arguments, "DNA: The 'a' is for 'acid.' Want to feed your kids acid?"

Lauren Giordano

"Safety always has to be the number one concern," Folta said. "And an understanding of safety is contingent on an understanding of the chemical in question. But she lacks the scientific prowess to be able to tell when something is truly a threat, and when something poses no threat."

Hari argues that the campaigns are really about a bigger picture; she wasn't honestly that concerned over the exact effects of azodicarbonamide, in particular. Rather, that campaign and others are allegories, in service of the point that food additives should be thoroughly tested for safety before they are put into food—instead of the current model, in which additives are removed after there is evidence of harm.

"The scientists who argue with me about this minute data, who keep saying 'The dose makes the poison,' Hari says, shaking her head. "Why aren't we more cautious about the ingredients we allow in our food supply? Why are we allowing all these additives? And what's the cumulative effect of all these additives together? That's something people are just starting to study."

Under the current system, food manufacturers can use ingredients without oversight by the Food and Drug Administration under an exemption where that ingredient is approved because it is "Generally Regarded as Safe" (GRAS). Many agree that the process makes sense for some basic substances that have long been in use, like salt. But as the list of chemical additives has grown into the thousands, many believe that safety oversight is lacking, and that the GRAS exemption is not being used as intended. As the Environmental Working Group argues, for one, "This system makes sense for benign additives such as pepper and basil, but there are enormous loopholes that allow additives of questionable safety to be listed as GRAS."

"If there's not enough data to say that these chemicals are safe, I say, use the precautionary principle and don't use them," said Hari. "Especially if other countries have enough concern to ban a chemical," as was the case with azodicarbonamide in Europe. The GRAS process has come under additional scrutiny in recent years, including a study in JAMA Internal Medicine that tracked GRAS designation for chemicals introduced between 1997 and 2012. It found that 22 percent of the scientists charged with making the determinations of what "generally regarded as safe" meant in each case were employees of company that manufactured the additive in question. In other cases, the scientists were selected by the manufacturers. None were selected by a disinterested third party.

"There's disconnect between the language of science and the language of common communication," Folta said, explaining why, while many people are upset over the GRAS system, it doesn't bother him. "You can never demonstrate that something is 'safe.' Whether it's water or sugar; there's no way. Because you can't test every aspect. All we can say is, of all the things we've looked at, there's no evidence of harm. If you said, can you prove to me beyond a shadow of a doubt that something is safe, I'd say, no way. With vaccines, sure, you can't account for some extremely rare effect that might be seen in someone with a particular metabolic disorder, but that's not to say they're not a tremendous benefit to society as a whole."

Hari understands that science cannot prove a negative—that studies can prove that something can happen, and studies can say that things are unlikely, but not impossible—so some chance of harm can never be totally ruled out. That aside, she believes that testing should be more stringent. Her end game, she says, is to reform the FDA process.

So, she says, "Take McDonald's French fries," as a good example of her approach. "In the U.K., they have four ingredients. In the U.S., they have 19. What are these 15 extra ingredients? Why do we need those in our bodies? Those are the questions I'm asking."

"Even though her heart's in the right place, and I understand what she's going for," Folta conceded, beginning to get at the practicalities of the disconnect, "you don't use coercion and intimidation to achieve a scientific end."

It is the issue of GMOs where Hari's messages come into clearest conflict with Folta's work. The lab next to his at the University of Florida, he tells me, for example, has produced a tomato seed that will yield a fruit that is loaded with folic acid—a vitamin that is proven to dramatically reduce the risk of neural tube defects like spina bifida in infants. Folic acid is, for pregnant women, actually, one of the only cases in which vitamin supplementation is proven to be beneficial to human beings. But it must be taken very early in pregnancy, during the period before many women know that they are pregnant. So, at least in theory, a folate-rich tomato that made its way into mainstream use could prevent some serious birth defects.

The tomato is one of many GMOs that exist in laboratories—not just high-vitamin fruits, but plants that can grow in drought, or in extreme heat—that go unused, Folta laments, because the licensing process for new crops, through the FDA and EPA, is costly and arduous. The high-folate tomato would be most-needed outside of the U.S., where nutrient-poor diets are more common. An agricultural biotechnology company is unlikely to spend millions in development where there is no lucrative market.

Moving a gene that gives disease resistance from spinach into strawberries, in order to make them immune from disease is—an example of existing GMO technology—is in Folta's view, an unquestionable triumph of science. It's not unlike the synthetic insulin that is given to people with diabetes around the world, or the pacemakers that can be implanted in a person's chest.

In this way, Hari's anti-GMO messages hit very close to home for Folta. In the book, Hari's case against many foods is predicated on the fact that they contain GMOs, implying that this is a concern for human health, despite the fact that the U.S. National Academy of Sciences, the World Health Organization, the U.K. Royal Society, the French Academy of Sciences, and the European Commission have all concluded that foods derived from genetically modified crops pose no risk to human health. No case of human illness or allergy has ever been directly attributed to genetically modified crops. So noted Michael Specter last summer in a New Yorker profile of environmentalist Vandana Shiva, who is leading a global spiritual crusade against genetically modified crops.

Hari described the article as an "industry-funded" attack. She advised me to read Shiva's response. In it, Shiva accuses Specter of poor journalism and outright fraud in service of the biotech industry. She asks if Specter's work is "sponsored by the GMO movement" and if he is involved in publicity for Monsanto on behalf of Condé Nast (publisher of The New Yorker), before escalating the charges against Specter to character assassination and slander.

Wariness of commercial interests and financial conflicts is obviously critical to honest discussion about the future of feeding the planet. But to accuse anyone who defends the use of GMOs of industry corruption, of being a shill for industry, stifles much-needed conversation. It is simply impossible that every scientist who argues for the benefits of genetic modification is sacrificing ethics and academic integrity for a paycheck from a biotech company. But that is the party line among detractors. Really the long tails of commercial interests factor, at times, on both sides.

"Vani is very good at marketing herself and telling people what they want to hear," Folta said. "She is very good at playing into the current popularity of vilifying farmers and large-scale agriculture. But really, she's her own company, and she's the spokesperson." Indeed, Hari does sell products through her web site. Readers can choose from among an impressive array of juicers. And if you order the book today, you will also receive The Food Babe's "Guide to Grocery Shopping," including a list of her favorite brands ($29.99 value) for free.

Hari, likewise, accuses Folta of conflicts of interest through ties to Monsanto, specifically due to his involvement with a project called GMO Answers. He admits to having industry friends and open lines of communication with biotechnology companies, and he has spoken at Monsanto. He understands the job of the academic scientist to include helping farmers optimize whatever seeds they have "whether they come from Monsanto or Johnny's Organic Seeds in Vermont"—where he'd also gladly speak. But he denies financial ties.

"I didn't work for 30 years in this business as a public scientist, at half the salary of what I could earn working for industry, so that I could sell out for some company," he explained. "She has called me a professor who works for Monsanto, which is the most insane thing I've ever heard. I work for the state of Florida. But she had to play that card to discredit me, because I'm hitting a little too close to home with her whole scam."

Folta understands his calling on noble terms, his charge to create solutions that help people and the environment and farmers. "That's what we do every day. That's why we get out of bed," he said.

Both believe themselves to be outsiders, fighting an unjust system that locks them out, the result of misinformed public opinion. "We can come up with ideas to solve real problems, and we can't use them because the regulatory system is too stringent," Folta said. "That's in reaction to public outcry. Having solutions that we believe will help people and help the planet, and yet we can't deploy them, is one of the most frustrating things. To have someone like Hari go out and make up nonsense that only digs into public opinion against these technologies is really frustrating for us."

"Do you worry about some kind of nutritional impact of GMOs?" I asked Hari. "Or is it an environmental argument?"

"I worry more about the number of pesticides that are associated with GMOs. For me it's a pesticide issue, when it comes to eating them," she said, pointing me to an article by Tom Philpott in Mother Jones in 2012, "How GMOs Unleashed a Pesticide Gusher" (and applauding the effectiveness of "gusher" in the headline). Folta counters that while herbicides may have increased, because herbicide-resistant seeds have allowed for increased use of weed-killers like glyphosate, insecticide use has actually decreased, because the crop itself can be insect-resistant. When a bug eats certain GMO corn or cotton, for example, a protein in the plant kills the bug, eradicating infestation.

"Now, from a morality and human rights perspective," Hari continued, "it's un-American that companies don't allow us to know if a product contains GMO ingredients." Indeed, a substantial majority of Americans do favor requiring food labels to disclose the use of GMOs, even if that information might imply health concerns that have not been observed. But knowing that labeling would be detrimental to bottom lines, companies have lobbied against that requirement. Or, as Hari sees it, "We've got a whole industry that's scared to tell us that they're serving us GMOs."

"There's value to people having concerns about food and wanting to communicate science to the public, and she's gifted in that regard," Folta said. "I certainly recognize that she has great influence, and that's wonderful. The trick now is, how do you get someone like her to consult me rather than another activist? To talk with scientists who can work with her to give her good information? I don't want to throw her under the bus; I want her to get on the bus."

But as these debates heat, and each side feels beleaguered and attacked, it's more likely that discussion will become more polarized. Each side will lecture the other in the ways of science, even while both believe that everything they do is firmly rooted in science. Each will position itself with only the noblest of aspirations, accusing the other of unduly prioritizing financial gain. And the conflict will, at least, keep these critical topics in the public eye.

Hari told me that she is looking for new campaigns, constantly. And as she learned the business of media and marketing, she is also learning the science of nutrition and sustainability. I could never entirely parse her sense of deep-seated corruption that informs the sweeping claims about entire professions and industries. Convenient as it is as a device, it also feels sincere. And it's pervasive. In the book she writes it most pointedly: "You can't trust anyone but yourself."

At times, even, Hari's suspicions lead her to contradict the basic tenet that natural is good. "Readers of my blog know," she writes in the book, "that the next time you lick vanilla ice cream from a cone, there’s a good chance you’ll be swirling secretions from a beaver’s anal glands around in your mouth." Indeed. "Called castoreum, this secretion is used as a 'natural flavor' not only in vanilla ice cream but also in strawberry oatmeal and raspberry-flavored products." And, similarly, "If you chew gum, you may also be chewing lanolin, an oily secretion found in sheep’s wool that is used to soften some gums. What nutritional value do you think these disgusting additives have for your body? None! They exist just to get you to buy something fake or that shouldn’t be food, rather than a real alternative.”

In her recent campaign against the many ingredients in beer, Hari got into a debate over whether some beers do contain an additive derived from the swim bladder of a fish.

Which is natural, I pointed out.

"Which is natural. It's just a great ingredient to point out. Because people are like, what?"

And unless I am grossly misled by her bodily reactions at their mention, she really does care about fish bladders. Fear-mongering, to me, is intentionally riling people up. Sharing genuine concerns is just in the nature of a wary person. "I have a ton of vegan and vegetarian friends," Hari said. "They would want to know if there are fish bladders in their beer."

Hari recently implemented an editorial policy on the site wherein any change or correction will be noted ("I make mistakes, I'm human."). And she will be announcing an advisory board that will help to review her claims. She will continue to be, as she has already proven, relentless and purposeful and clearly effective. It may be too optimistic to think that both sides of these debates can grow together and learn from one another's concerns and perspectives, but the opportunity is certainly there. Until then, the battle for moral high ground marches on.

"I want to be in a position where, if I die tomorrow," Hari said, "I can say I did everything I possibly could to bring awareness to the public, and to lead some lasting change."

"I hope you don't die tomorrow," I said, struck by the dramatic hypothetical.

"If I die tomorrow," she continued. "I'm going to be so pissed."

She did not. But after two and a half hours of talking with me, she did look down and notice that she had been drinking Tazo, a brand of green tea with which she has taken issue on her blog because it contains "natural flavors," and she was genuinely disappointed.