“People could point to these things and say, ‘They’ve got too much sugar, they’ve got too much salt,’ ” Bible said. “Well, that’s what the consumer wants, and we’re not putting a gun to their head to eat it. That’s what they want. If we give them less, they’ll buy less, and the competitor will get our market. So you’re sort of trapped.” (Bible would later press Kraft to reconsider its reliance on salt, sugar and fat.) When it came to Lunchables, they did try to add more healthful ingredients. Back at the start, Drane experimented with fresh carrots but quickly gave up on that, since fresh components didn’t work within the constraints of the processed-food system, which typically required weeks or months of transport and storage before the food arrived at the grocery store. Later, a low-fat version of the trays was developed, using meats and cheese and crackers that were formulated with less fat, but it tasted inferior, sold poorly and was quickly scrapped. When I met with Kraft officials in 2011 to discuss their products and policies on nutrition, they had dropped the Maxed Out line and were trying to improve the nutritional profile of Lunchables through smaller, incremental changes that were less noticeable to consumers. Across the Lunchables line, they said they had reduced the salt, sugar and fat by about 10 percent, and new versions, featuring mandarin-orange and pineapple slices, were in development. These would be promoted as more healthful versions, with “fresh fruit,” but their list of ingredients — containing upward of 70 items, with sucrose, corn syrup, high-fructose corn syrup and fruit concentrate all in the same tray — have been met with intense criticism from outside the industry. One of the company’s responses to criticism is that kids don’t eat the Lunchables every day — on top of which, when it came to trying to feed them more healthful foods, kids themselves were unreliable. When their parents packed fresh carrots, apples and water, they couldn’t be trusted to eat them. Once in school, they often trashed the healthful stuff in their brown bags to get right to the sweets. This idea — that kids are in control — would become a key concept in the evolving marketing campaigns for the trays. In what would prove to be their greatest achievement of all, the Lunchables team would delve into adolescent psychology to discover that it wasn’t the food in the trays that excited the kids; it was the feeling of power it brought to their lives. As Bob Eckert, then the C.E.O. of Kraft, put it in 1999: “Lunchables aren’t about lunch. It’s about kids being able to put together what they want to eat, anytime, anywhere.” Kraft’s early Lunchables campaign targeted mothers. They might be too distracted by work to make a lunch, but they loved their kids enough to offer them this prepackaged gift. But as the focus swung toward kids, Saturday-morning cartoons started carrying an ad that offered a different message: “All day, you gotta do what they say,” the ads said. “But lunchtime is all yours.” With this marketing strategy in place and pizza Lunchables — the crust in one compartment, the cheese, pepperoni and sauce in others — proving to be a runaway success, the entire world of fast food suddenly opened up for Kraft to pursue. They came out with a Mexican-themed Lunchables called Beef Taco Wraps; a Mini Burgers Lunchables; a Mini Hot Dog Lunchable, which also happened to provide a way for Oscar Mayer to sell its wieners. By 1999, pancakes — which included syrup, icing, Lifesavers candy and Tang, for a whopping 76 grams of sugar — and waffles were, for a time, part of the Lunchables franchise as well. Annual sales kept climbing, past $500 million, past $800 million; at last count, including sales in Britain, they were approaching the $1 billion mark. Lunchables was more than a hit; it was now its own category. Eventually, more than 60 varieties of Lunchables and other brands of trays would show up in the grocery stores. In 2007, Kraft even tried a Lunchables Jr. for 3- to 5-year-olds. In the trove of records that document the rise of the Lunchables and the sweeping change it brought to lunchtime habits, I came across a photograph of Bob Drane’s daughter, which he had slipped into the Lunchables presentation he showed to food developers. The picture was taken on Monica Drane’s wedding day in 1989, and she was standing outside the family’s home in Madison, a beautiful bride in a white wedding dress, holding one of the brand-new yellow trays. During the course of reporting, I finally had a chance to ask her about it. Was she really that much of a fan? “There must have been some in the fridge,” she told me. “I probably just took one out before we went to the church. My mom had joked that it was really like their fourth child, my dad invested so much time and energy on it.” Monica Drane had three of her own children by the time we spoke, ages 10, 14 and 17. “I don’t think my kids have ever eaten a Lunchable,” she told me. “They know they exist and that Grandpa Bob invented them. But we eat very healthfully.”

. ‘It’s Called Vanishing Caloric Density.’ At a symposium for nutrition scientists in Los Angeles on Feb. 15, 1985, a professor of pharmacology from Helsinki named Heikki Karppanen told the remarkable story of Finland’s effort to address its salt habit. In the late 1970s, the Finns were consuming huge amounts of sodium, eating on average more than two teaspoons of salt a day. As a result, the country had developed significant issues with high blood pressure, and men in the eastern part of Finland had the highest rate of fatal cardiovascular disease in the world. Research showed that this plague was not just a quirk of genetics or a result of a sedentary lifestyle — it was also owing to processed foods. So when Finnish authorities moved to address the problem, they went right after the manufacturers. (The Finnish response worked. Every grocery item that was heavy in salt would come to be marked prominently with the warning “High Salt Content.” By 2007, Finland’s per capita consumption of salt had dropped by a third, and this shift — along with improved medical care — was accompanied by a 75 percent to 80 percent decline in the number of deaths from strokes and heart disease.) Karppanen’s presentation was met with applause, but one man in the crowd seemed particularly intrigued by the presentation, and as Karppanen left the stage, the man intercepted him and asked if they could talk more over dinner.

Their conversation later that night was not at all what Karppanen was expecting. His host did indeed have an interest in salt, but from quite a different vantage point: the man’s name was Robert I-San Lin, and from 1974 to 1982, he worked as the chief scientist for Frito-Lay, the nearly $3-billion-a-year manufacturer of Lay’s, Doritos, Cheetos and Fritos. Lin’s time at Frito-Lay coincided with the first attacks by nutrition advocates on salty foods and the first calls for federal regulators to reclassify salt as a “risky” food additive, which could have subjected it to severe controls. No company took this threat more seriously — or more personally — than Frito-Lay, Lin explained to Karppanen over their dinner. Three years after he left Frito-Lay, he was still anguished over his inability to effectively change the company’s recipes and practices. By chance, I ran across a letter that Lin sent to Karppanen three weeks after that dinner, buried in some files to which I had gained access. Attached to the letter was a memo written when Lin was at Frito-Lay, which detailed some of the company’s efforts in defending salt. I tracked Lin down in Irvine, Calif., where we spent several days going through the internal company memos, strategy papers and handwritten notes he had kept. The documents were evidence of the concern that Lin had for consumers and of the company’s intent on using science not to address the health concerns but to thwart them. While at Frito-Lay, Lin and other company scientists spoke openly about the country’s excessive consumption of sodium and the fact that, as Lin said to me on more than one occasion, “people get addicted to salt.”

Not much had changed by 1986, except Frito-Lay found itself on a rare cold streak. The company had introduced a series of high-profile products that failed miserably. Toppels, a cracker with cheese topping; Stuffers, a shell with a variety of fillings; Rumbles, a bite-size granola snack — they all came and went in a blink, and the company took a $52 million hit. Around that time, the marketing team was joined by Dwight Riskey, an expert on cravings who had been a fellow at the Monell Chemical Senses Center in Philadelphia, where he was part of a team of scientists that found that people could beat their salt habits simply by refraining from salty foods long enough for their taste buds to return to a normal level of sensitivity. He had also done work on the bliss point, showing how a product’s allure is contextual, shaped partly by the other foods a person is eating, and that it changes as people age. This seemed to help explain why Frito-Lay was having so much trouble selling new snacks. The largest single block of customers, the baby boomers, had begun hitting middle age. According to the research, this suggested that their liking for salty snacks — both in the concentration of salt and how much they ate — would be tapering off. Along with the rest of the snack-food industry, Frito-Lay anticipated lower sales because of an aging population, and marketing plans were adjusted to focus even more intently on younger consumers. Except that snack sales didn’t decline as everyone had projected, Frito-Lay’s doomed product launches notwithstanding. Poring over data one day in his home office, trying to understand just who was consuming all the snack food, Riskey realized that he and his colleagues had been misreading things all along. They had been measuring the snacking habits of different age groups and were seeing what they expected to see, that older consumers ate less than those in their 20s. But what they weren’t measuring, Riskey realized, is how those snacking habits of the boomers compared to themselves when they were in their 20s. When he called up a new set of sales data and performed what’s called a cohort study, following a single group over time, a far more encouraging picture — for Frito-Lay, anyway — emerged. The baby boomers were not eating fewer salty snacks as they aged. “In fact, as those people aged, their consumption of all those segments — the cookies, the crackers, the candy, the chips — was going up,” Riskey said. “They were not only eating what they ate when they were younger, they were eating more of it.” In fact, everyone in the country, on average, was eating more salty snacks than they used to.