Salt Sugar Fat: How the Food Giants Hooked Us (5 page)

One of Monell’s sponsors, Frito-Lay, was particularly interested in the salt part of the study, since the company made most of its money on salty chips. Citing Monell’s work in a 1980 internal memo, a Frito-Lay food
scientist summed up the finding on kids and added, “Racial Effect: It has been shown that blacks (in particular, black adolescents) displayed the greatest preference for a high concentration of salt.” The Monell scientist who did this groundbreaking study, however, raised another issue that reflected his anxiety about the food industry. Kids didn’t just
like
sugar more than adults, this scientist, Lawrence Greene, pointed out in a paper published in 1975. Data showed they were actually consuming more of the stuff, and Greene suggested there might be a chicken-and-egg issue at play: Some of this craving for sugar may not be innate in kids but rather is the result of the massive amounts of sugar being added to processed foods. Scientists call this a learned behavior, and Greene was one of the first to suggest that the increasingly sweet American diet could be driving the desire for more sugar, which, he wrote, “may or may not correspond to optimum nutritional practices.”

In other words, the sweeter the industry made its food, the sweeter kids liked their food to be.

I wanted to explore this idea a bit more deeply, so I spent some time with Julie Mennella, a biopsychologist who first came to Monell in 1988. In graduate school, she had studied maternal behavior in animals and realized that no one was examining the influence that food and flavors had on women who were mothers. She joined Monell to answer a set of unknowns about food. Do the flavors of the food you eat transmit to your milk? Do they transmit to amniotic fluid? Do babies develop likes and dislikes for foods even
before
they are born?

“One of the most fundamental mysteries is why we like the foods that we do,” Mennella said. “The liking of sweet is part of the basic biology of a child. When you think of the taste system, it makes one of the most important decisions of all: whether to accept a food. And, once we do, to warn the digestive system of impending nutrients. The taste system is our gatekeeper and one of the research approaches has been to take a developmental route, to look from the beginning—and what you see is that children are living in different sensory worlds than you and I. As a group, they prefer much higher levels of sweet and salt, rejecting bitter more than we do. I
would argue that part of the reason children like high levels of sweet and salt is a reflection of their basic biology.”

Twenty-five years later, Mennella has gotten closer than any other scientist to one of the most compelling—and, to the food industry, financially important—aspects of the relationship kids have to sugar. In her most recent project, she tested 356 children, ages five to ten, who were brought to Monell to determine
their “bliss point” for sugar. The bliss point is the precise amount of sweetness—no more, no less—that makes food and drink most enjoyable. She was finishing up this project in the fall of 2010 when she agreed to show me some of the methods she had developed. Before we got started, I did a little research on the term
bliss point
itself. Its origins are murky, having some roots in economic theory. In relation to sugar, however, the term appears to have been coined in the 1970s by a Boston mathematician named Joseph Balintfy, who used computer modeling to predict eating behavior. The concept has obsessed the food industry ever since.

Food technicians typically refer to the bliss point privately when they are perfecting the formulas for their products, from sodas to flavored potato chips, but oddly enough, the industry has also sought to use the bliss point in defending itself from criticism that it was jamming the grocery store with foods that create unhealthy cravings. In 1991, this view of the bliss point as a natural phenomenon took center stage at a gathering of one of the more unusual industry associations. Based in London,
the group was called ARISE (Associates for Research into the Science of Enjoyment), and its sponsors included food and tobacco companies. ARISE saw its mission as mounting a “resistance to the ‘Calvinistic’ attacks on people who are obtaining pleasure without harming others.” The meeting, held in Venice, Italy, started off with a British scientist who discussed what he called “moreishness,” in which the early moments of eating—as in appetizers—were shown to be valuable in the pursuit of pleasure by actually making you hungrier still. Monell’s own director, Gary Beauchamp, gave a presentation in which he detailed the varied responses that infants have to tastes. Children developed a taste for salt as early as four or five
months, he told the assembled scientists, while their liking for sweet appears to be in place the moment they are born.

The next presenter was an Australian psychologist named Robert McBride, who captivated the audience with a presentation he called “The Bliss Point: Implication for Product Choice.”

Food manufacturers need not fear the implication of pleasure in the word
bliss
, he began. After all, he said, who among us chooses food based on its nutritional status? People pick products off the grocery shelf based on how they expect them to taste and feel in their mouths, not to mention the signals of pleasure their brains will discharge as a reward for choosing the tastiest foods. “Nutrition is not foremost on people’s mind when they choose their food,” he said. “It’s the taste, the flavor, the sensory satisfaction.”

And when it comes to these attributes, none is more powerful—or more conducive to being framed by the bliss point—than the taste of sugar, he said. “Humans like sweetness, but how much sweetness? For all ingredients in food and drink, there is an optimum concentration at which the sensory pleasure is maximal. This optimum level is called the bliss point. The bliss point is a powerful phenomenon and dictates what we eat and drink more than we realize.”

The only real challenge for companies when it comes to the bliss point is ensuring that their products hit this sweet spot dead on. Companies are not going to sell as much ketchup, Go-Gurt, or loaves of bread if they’re not sweet enough. Or, put a different way, they will sell a lot more ketchup, Go-Gurt, and loaves of bread if they can determine the precise bliss point for sugar in each of those items.

McBride ended his presentation that day in Venice with words of encouragement for the food company attendees. With a little work, he said, the bliss point can be computed and totted up like so much protein or fiber or calcium in food. It may not be something that companies would want to put on their labels, like they do in boasting about a product’s infusion with vitamins. But the bliss point was, nonetheless, just as real and important to their customers.

“Pleasure from food is not a diffuse concept,” he said. “It can be measured just as the physical, chemical, and nutritional factors can be measured. With more concrete status, the capacity of food flavors to evoke pleasure may start to be regarded as a real, tangible property of products, along with their nutritional status.”

J
ulie Mennella, the biopsychologist at Monell, agreed to show me how the bliss point is calculated. I returned to the center on a warm day in November, and she took me into a small tasting room, where we met our guinea pig:
an adorable six-year-old girl named Tatyana Gray. Tatyana had brightly colored beads in her hair and a pink T-shirt that read “5-Cent Bubble Gum” across the front. The expression on her face was one of cool professionalism: This was a job she could handle.

“What’s your favorite cereal in the whole world?” Mennella asked Tatyana, just for fun.

“My favorite cereal is … Cinnamon CRUNCH,” Tatyana replied.

Tatyana sat at a small table, with little stuffed versions of Big Bird and Oscar the Grouch perched next to her. As a lab assistant started to assemble the food to be tested, Mennella explained that the protocol for this experiment had been derived from twenty years of trials and was designed to elicit a scientifically measurable response. “We are dealing with foods that are very well liked, and so we’re going to ask the child which one they like
better
. The one they like better, they are going to give to Big Bird because they know he likes things that taste good. We’re looking at a wide range of children, as young as three, and we don’t want language to play a role here. The child doesn’t have to say anything. They either point to the one they like, or in this case, they give it to Big Bird. It’s meant to minimize the impact of language.”

Why not just ask the kids straight out if they like it? I asked.

“It just doesn’t work, especially for the young ones,” she said. “You can give them everything and they will say yes or no. Though, in this context,
it tends to be yes. Children are smart. They’ll tell you what they think you want to hear.”

We tested this notion out by asking Tatyana which she preferred: broccoli or the Philadelphia-made snack called the TastyKake.

“Broccoli,” she said, ready for a pat on the head.

For our bliss point test, Mennella’s assistant had whipped up a dozen vanilla puddings, each at a different level of sweetness. She started by putting two of the variations into small plastic cups and setting them in front of Tatyana. Tatyana tasted the one on the left, swallowed, and took a sip of water. Then she tasted the one on the right. She didn’t speak, but she didn’t have to. Her face lit up as her tongue pressed into the roof of her mouth, pushing the pudding into the thousands of receptors waiting for sweetness. Being an old hand at the test, she ignored the stuffed animals and simply pointed to the cup she preferred.

There was one problem with watching Tatyana work her way through the puddings, though. So much was going on in creating the bliss she felt that was invisible to us. Each little spoonful disappeared into her mouth, and we could see her facial expressions and, ultimately, her decision. But in between tasting and choosing, a whole chain of events was unfolding inside her body, starting with her taste buds, that was critical to understanding how and why she was so happy.

To better understand what, exactly, was going on, I turned to another Monell scientist, Danielle Reed, who had trained in psychology at Yale. Reed, when we met, was using quantitative genetics to examine how inheritance might affect the pleasure we derive from sensations like tasting sugar, but her research on the sweet taste has also focused on the mechanics. Reed was among the group at Monell who discovered T1R3, the sweet receptor protein. She told me that Tatyana’s swoon for the sugar in the pudding begins with her saliva. After all, we don’t call tasty food “mouthwatering” for nothing. The mere sight of a sugary treat will start the saliva flowing, which in turn primes the digestive system. “The sugar, or sweet molecule, dissolves in your saliva,” Reed said. Our taste buds are not smooth little bumps like we might imagine, she explained. They have
clumps of tiny, hair-like fronds that rise up from the bud, and it’s these fronds, called microvilli, that hold the cell that detects and receives the taste. “And that sets off a series of chain reactions inside the cell. So that the taste receptor cell talks to its friends in the taste bud. There is a lot of microprocessing of that signal, and then eventually it decides that what is in your mouth is sweet, and it squirts out neurotransmitters onto the nerve, which then goes to the brain.”

Like most everything that goes on inside the brain, what happens up there in relation to food is still being sorted out. But researchers are beginning to chart the pathway that sugar takes—which Reed described as more of a deliberate march. “There is a very orderly progress of pathways in the brain that people are just now starting to learn,” she said. “It stops at the first relay station and moves forward and forward and it eventually ends up in the pleasure centers, like the orbital frontal cortex of the brain, and that’s when you have the experience, ‘Ahh, sweet.’ The
good
aspect of sweet.”

We don’t even have to eat sugar to feel its allure. Pizza will do, or any other refined starch, which the body converts to sugar—starting right in the mouth, with an enzyme called amylase. “The faster the starch becomes sugar, the quicker our brain gets the reward for it,” Reed said. “We like the highly refined things because they bring us immediate pleasure, associated with high sugar, but obviously there are consequences. It’s sort of like if you drink alcohol really fast, you get drunk really fast. When you break down sugar really fast your body gets flooded with sugar more than it can handle, whereas with a whole grain it is more gradual and you can digest it in a more orderly fashion.”

In the testing that Mennella conducted to calculate Tatyana’s bliss point for sugar, the six-year-old worked her way through two dozen puddings, each prepared to a different level of sweetness. The puddings were presented to her in pairs, from which she would choose the one she liked more. Each of her choices dictated what pudding pair would come next, and slowly Tatyana moved toward the level of sweetness she preferred most of all. When Mennella got the results, it was plain to see that there was no way Tatyana would ever have fed Big Bird a twig of broccoli over a Krimpet,
a Kreamie, or anything else from the TastyKake line. Tatyana’s bliss point for the pudding was 24 percent sugar, twice the level of sweetness that most adults can handle in pudding. As far as children go, she was on the lower side; some go as high as 36 percent.

“What we find is that the foods that are targeted to children, the cereals and the beverages, they are way up,” Mennella said. “Tatyana’s favorite cereal is Cinnamon Crunch, and what we’ll do, we’ll measure the level of sweetness that the child prefers in the laboratory with a sucrose solution and it matches the sugar content of the most preferred cereal. There are individual differences, but as a group, in every culture that has been studied around the world, children prefer more intense sweetness than adults.”

Beyond the basic biology, there are three other aspects of sugar that seem to make it attractive to children, Mennella said. One, the sweet taste is their signal for foods that are rich in energy, and since kids are growing so fast, their bodies crave foods that provide quick fuel. Two, as humans, we didn’t evolve in an environment that had lots of intensely sweet foods, which probably heightens the excitement we feel when we eat sugar. And finally, sugar makes children feel good. “It’s an analgesic,” Mennella said. “It will reduce crying in a newborn baby. A young child can keep their hand in a cold water bath longer if a sweet taste is in their mouth.”