October 2008 Issue

Taste Better, Live Better — Using Flavor to Retrain Palates and Fill Up on Less
By Juliann Schaeffer
Today’s Dietitian
Vol. 10 No. 10 P. 54

Who says you can’t teach an old tongue new tricks?

According to Marcia Levin Pelchat, PhD, an associate member of the Monell Chemical Senses Center in Philadelphia, “People tend to eat what they like.” But what happens when what many people like represents a revolving door that circles around highly processed foods and an excess of salt, sugar, and fat? America, and largely the world, is feeling the devastating effects that such a diet has on the body, with epidemic proportions of overweight and obesity and an overabundance of diabetes and heart disease diagnoses to boot.

Part of the problem, which David L. Katz, MD, MPH, FACPM, FACP, director of Yale University’s Prevention Research Center, has long been contemplating, lies in the following question: “Why don’t people simply eat more fruits and vegetables? Why is junk food so appealing? Fundamentally, it’s very interesting to wonder, given that food is the fuel that the human body runs on, why doesn’t the body just naturally crave the fuel that’s best for it?”

Perhaps looking at the problem from a different perspective could open up alternatives for solutions. Imagine a world where people actually crave an apple for an afternoon snack and fresh salmon with steamed broccoli for dinner, or one where people feel full after eating a balanced meal, no longer needing to indulge in excess to reach satiety? Would the preventable health conditions that many dietitians deal with daily run so rampant if clients actually desired healthier food or filled up faster? Some experts say this world can be a reality, but it takes work and it’s no easy fix. To figure out why people even crave unhealthy and processed foods, the science of flavor needs examining.

The Science Behind Flavor
According to Pelchat, universal traits or biases toward flavor exist at birth, with almost everyone born liking sweet and disliking bitter tastes. Humans’ affinity for sweetness is actually apparent even before birth. “In the [past], when there was too much fluid in the womb, one of the ways to remove [it] was to have the fetus swallow it. It goes out through the umbilical cord, is then processed by the mother’s kidneys, and leaves in a very natural way. So if there’s a buildup of fluid, they would inject saccharin in the womb so the fetus would swallow more,” she says.

Evolutionarily, Pelchat says sweetness was likely a signal for ripe fruit and nutrients, with bitterness signifying toxins.

Salty tastes are slightly different from sweet and bitter tastes, and Pelchat says there’s no evidence that human infants can detect salt at birth. “But by the time they’re 4 or 5 months of age, they are able to detect it. We think that the ability to detect salt has to mature. But once infants show a response to salt solutions, they like them,” she says.

However, Pelchat points out that culture and experience modify the palate response to what is deemed an appropriate context of sweet and bitter tastes. “What we call French dressing is very sweet. But to [the French], salad dressing really shouldn’t be sweet. And for bitterness, although we’re all born not liking bitter, as adults, we almost all consume some bitter things, like coffee, marmalade, or beer. It’s not that people just learn to tolerate them; they can actually learn through experience to enjoy the bitter in these foods.”

But don’t mistakenly think that taste preference only factors in taste. “When you talk about taste preferences, you’re really talking about flavor,” says Pelchat. “Flavor is a combination of many sensory inputs, and the two major ones are taste and smell. Unlike the sense of taste, as far as we can tell, food odor preferences (and in fact odor preferences of any kind) seem to be learned through experience.”

Pelchat explains that if a novel aroma is paired with sweetness in a solution, people will increase their liking for that aroma. “We don’t think there are really any inborn preferences for the aromatic component of flavor but that they’re all learned,” she says.

To illustrate this concept further, consider this: “There are only a limited number of basic tastes, yet we can experience untold thousands of different flavors,” says Pelchat. “When you think about it, all fruits are sweet and a little bit sour (except for some that are just pretty much sweet), and the thing that makes different fruits different is really the aromatic component of flavor. The thing that makes beef different from lamb is aroma. Meatiness may come from umami [savory taste], but species identification comes from smell.”

Pelchat argues that the sense of smell is a very informative part of flavor. “It allows you to make much finer distinctions among foods than would taste alone. Taste is really important for encouraging people to eat, but I would argue that the sense of smell is much more informative than the sense of taste.”

Dawn Jackson Blatner, RD, LDN, an American Dietetic Association spokesperson and the author of The Flexitarian Diet, says that while we may be born with certain taste preferences, environmental factors can be much more important in determining what foods people gravitate toward. “Availability, accessibility, parental and peer consumption, exposure to foods, and habit all play a role in what foods we enjoy,” she says.

Retraining Your Taste Buds
For those accustomed to snacking on Doritos and heading to the local McDonald’s for dinner, the natural sweetness in bananas can be hard to detect or even unsatisfying. Jeannie Houchins, MA, RD, a food and nutrition consultant, doesn’t think the typical American diet, which tends to be high in processed foods, is desensitizing taste buds, but she says people are instead training themselves to eat certain foods that may not be what the body needs. “Employing an elimination diet where one removes highly processed foods and reintroduces foods in their most natural state can reverse this habit. Eating whole, ripe fruits and vegetables are good examples,” she suggests.

Blatner finds that her clients who are hooked on processed foods often lose their appreciation for the natural flavors in whole foods. “For example, fruit is naturally sweet, but these patients often lose their appreciation for this more natural, subtle fruit sweetness because they are looking for that ‘hypersweet’ taste they find in processed, refined, artificial foods,” she says.

But with the many factors involved in taste and flavor preference, is it scientifically possible to retrain a “processed” palate to not only eat but also enjoy a lower salt, fat, or sugar diet? Pelchat says it isn’t an easy fix, but it is certainly possible for people to modify their palate. “Monell’s director, Gary Beauchamp [PhD], did a small study on this, where he put [participants] on a low-salt diet, and their salt preferences did change. Their most preferred level of salt did go down with time,” she says, adding that it took roughly one month for participants’ preferences to change.

“And it was very easy to reverse the change in preference,” she adds. “If they went back to eating canned foods or fast foods that had a lot of salt in it, their preference for the higher salt level would go right back up. This has been shown as well with low-fat and low-sugar diets. It turns out that the change in preference is a sensory phenomenon.”

According to Pelchat, the actual taste of the salt surprisingly proved to be more important than the overall salt content in foods. “One of the things that Beauchamp and his collaborator did was to allow a subset of the subjects to add a little salt to the outside of their foods with a salt shaker, and they collected urinary sodium excretion data on all of their subjects,” she explains. “Even the ones that were adding salt to the food as it was served had a substantial decrease in sodium excretion. So they were eating a much lower salt diet than they had been before. But because they were getting the taste of salt on the outside of their food, their most preferred level of salt didn’t go down.”

She says the same thing can most likely be attributed to people who are consuming high-intensity sweeteners. “Obviously, the carbohydrate and calorie content of their diet goes down, but their preference for sweetness doesn’t change.”

To use this concept in your practice, Houchins says, “Slow introductions and being creative with natural foods is key. Most people are exposed to produce in stores that oftentimes are picked too soon, traveled many miles, and lack any flavor. It’s not often that people are exposed to a summer tomato or really sweet peaches.”

Because of this, Houchins says one of the best ways for clients to truly experience the best sweetness nature has to offer is to get them picking the produce themselves. “Heading out to a field to pick produce might not be feasible, so the next best thing is to select and eat produce that is in season to ensure the best flavor,” she says.

“Herbs and spices are great ways to also enhance the flavor of many foods in addition to keeping dishes economically sound (ie, not having to buy sauces, dressing, etc, which can be costly and caloric),” she adds of another way to get clients enjoying natural foods.

To successfully retrain clients’ palates, Blatner uses the following three techniques:

• increase availability and accessibility by purchasing more wholesome foods and keeping them easy to grab;

• practice patience and persistence by repeating exposure to healthy foods daily; and

• try flavor-flavor training by pairing unliked foods with liked flavors to authentically start liking unliked foods.

“For the fruit example, I would have patients buy more fruit and keep it easy to grab, aim to eat 2 cups of fruit every day, and experiment with fruit-based desserts such as broiled bananas with a drizzle of honey, grilled peaches with a dollop of low-fat yogurt, and baked apples with cinnamon,” Blatner says.

“There is a saying I use when working with patients: ‘The more you eat something, the more you want it.’ So if you eat lots of fast-food hamburgers and fries, you want more of them,” she adds. “But on the other hand, if you begin to eat lots of salads, you will soon crave salads.”

Pelchat agrees: “If you really do stick to a different diet, less processed foods and more whole foods, your preferences will change and your cravings will also change with time. The old ones will never go away. But we know that people who change their eating habits [eg, begin to eat more fish and salads] begin to crave those things if they’re no longer available. So [people] seem to be able to learn new cravings. And with time, the frequency of the new cravings should increase and the frequency of the old ones should decrease as the old environmental cues go away.”

Although Pelchat admits that it’s possible to retrain your palate, she says it’s difficult because every time people go back to old (and unhealthy) eating habits, food preferences will slide back to where they started. On a positive note, while it’s no magic pill, Pelchat says age is no obstacle for palate retraining. “Even older people can learn to like new foods, and that’s a group that is the target of a lot of diet change efforts because they’re the group that tends to develop diabetes and heart disease,” she says, noting that children, adults, and elders are all on the same playing field when it comes to palate modification.

Simplifying for Satiety’s Sake
Another dietary approach that considers flavor components is sensory-specific satiety. Katz, the author of The Flavor Point Diet: The Delicious Breakthrough Plan to Turn Off Your Hunger and Lose the Weight for Good, contends that it’s possible for clients to train themselves to fill up with fewer calories by focusing on flavor. He argues that flavor variety within meals stimulates appetite, increasing the caloric count required to achieve fullness.

Katz uses the traditional Thanksgiving dinner to illustrate: “It’s so common for people to eat until they’re absolutely stuffed and then immediately say, ‘What’s for dessert?’ It’s commonplace to make a joke about that, that there’s a hollow leg or an extra stomach in reserve for dessert. But there isn’t. We do anatomy in medical school, and there is no hollow leg and there is no extra stomach,” he says.

Katz says that while variety is the spice of life (and diet, too), too much variety can spice things up too much, especially when it comes to the kind of variety being added to many processed foods. “I’ve long been a dedicated student of food labels, and it’s really quite shocking that some breakfast cereals are much saltier than salty snacks. And some pasta sauces have much more added sugar than ice cream toppings,” he says.

“I don’t know whether the food industry figured this out or stumbled into it accidentally, but when you put more varieties of flavor into food and conceal one with the other, you turn on more appetite and people eat more,” he adds. And while this may be a good thing for food sellers, it can feel like sabotage for those watching their waistlines.

“The bottom line is that I believe there’s an overwhelming body of evidence that suggests that we’ve created a food supply with an incredible amount of variety available all the time, both among foods and within foods. And if your appetite is in overdrive, portion control is very tough; you’re going to be hungry and unsatisfied,” he says.

“And then there’s the obvious fact that the single most important thing about food is taste,” Katz explains. “That’s how we interact with food. If we know that limiting food to a simple flavor causes people to fill up faster, it really makes sense that having a wide variety of flavors engineered into foods would make people fill up slower and need to eat more. If you are choosing simpler foods and are arranging them in a reasonable pattern, you will fill up on fewer calories.”

The Flavor Point Diet describes how to eat by utilizing flavor categories so that your appetite isn’t turned on unnecessarily by eating salmon with a citrus vinaigrette, cheesy broccoli, and a salad with ranch dressing. However, Katz emphasizes that the concept’s substance isn’t so much in which flavors to put together; it’s the overall simplification of flavors that matters. “Avoid excessive variety in a given meal or a given snack,” he says. “For example, if you’re snacking during the day or you’re snacking in the evening, don’t cruise from one food to another.

“In terms of meals, try to have a harmony of flavors,” he continues. “Don’t have a different sauce and a different dressing on everything. If you are having grilled chicken or fish with a marinade, have a salad dressing that’s very similar to that marinade. A citrus marinade over fish works nicely if you have a citrus vinaigrette dressing over your salad. So simplify and harmonize.”

When trying to search for fewer flavor profiles in processed foods, Katz says the shorter the ingredient list, the better. “The closer you get to nature, the fewer unnecessary flavor additions there will be in that food, the more wholesome it is, and the fewer calories it takes to fill you up,” he says.

For clients wary of dumbing down their diet, explain that the fundamentals of sensory-specific satiety are avoiding excessive variety not over time but within meals. “Variety over time with diet is very important,” he emphasizes. “But don’t make every meal and snack a buffet or smorgasbord. That will absolutely kill any attempt to control calories. At the level of individual foods, choose foods that are minimally processed and close to nature.”

To use this concept in everyday life, Blatner says to focus on not having too many competing flavors in one meal. “At buffets, don’t have a little bite of everything. Instead, choose just your top three favorites. Limiting taste variety may be one factor to help control overeating,” she says.

The ultimate message that Katz wants the public to ponder is that portion control is hard if limiting how much you eat makes you hungry. The real goal for lifelong weight control is to be able to eat until you’re satisfied without taking in an excess of calories, and he says simplification is the answer. “Limit your choices at any given time to relatively simpler foods in relatively simpler combinations. And generally try to have a predominant flavor,” he says.

An added benefit of sensory-specific satiety is that the nudge toward simplification is a nudge toward better nutrition overall, says Katz. “It’s not just about taking off the pounds; it really is about improving the quality of the fuel your body runs on.”
Whether through retraining clients’ palates or simplifying flavor profiles within meals, clients may not only get healthier but, more importantly, enjoy the road to better nutrition so that they stay on it for the long haul.

— Juliann Schaeffer is an editorial assistant at Today’s Dietitian.