Food can be a comforting refuge when the going gets rough. Scientists estimate that as much as 75 percent of overeating is emotionally motivated. Depression, stress, or even boredom can lead just about anyone to reach for a tasty treat to make things seem a little better. What’s your favorite edible refuge?
Ice cream and other so-called “comfort foods” typically contain lots of sugar, fats, and carbohydrates, all of which lead to increased serotonin levels to moderate your mood. The sugar also prods your nucleus accumbens to release dopamine, further alleviating your stress. Eat slowly to avoid brain freeze!
How Your Body Perceives Food
Food for thought.
You probably think of eating food as something that you do with your hands and mouth—though, if you’re a person with good manners, you might also use utensils—and that the taste buds on your tongue are what tell you whether your meal is delicious or disappointing. But in reality, much of the experience of eating takes place in your brain, and other senses besides taste play a key role in determining what foods you find appealing and which ones you avoid. Moreover, your appetite and cravings for certain items and tastes was shaped in part by evolution, which selected characteristics that helped your ancestors to avoid malnutrition and food-borne illnesses. Modern marketers have figured out how to cleverly manipulate those cues to get us to buy their products, but with a little knowledge, we perhaps we can learn to avoid their wiles and take more control over what goes into our stomachs.
How Our Brains Taste Food
Now, we don’t want to take anything away from your mouth, which is equipped with some pretty powerful sensory equipment. Your taste buds—those tiny onion-shaped structures that mostly reside on your tongue—are pretty darn sensitive. Each of them has up to 100 taste-receptor cells, which have some of the properties of neurons. The taste buds send data to the chorda tympani, a branch of the facial nerve, and hyperglossal and glossopharyngeal nerves, which in turn transmit messages to your brainstem about that delicious orange slice of chocolate bon-bon upon which you’re munching.
Those receptors can sense five basic flavor qualities—salty, sour, bitter, sweet, and umami, which is the Japanese word for that meaty, mouthwatering sensation that you experience when you bite into a juicy steak.
Smell also is involved. As you gobble down food and it moves through the back of your throat, it reaches olfactory nerve endings in the roof of your nerve. Molecules from the food bind to those nerve endings, which in turn transmit data about the food’s aroma that end up in the temporal lobe of your brain. Smell is such a powerful component of taste that in experiments, researchers have trained rats to associate sweetness with an aroma and then caused their brains to react as if they’d tasted sugar, simply by spraying the scent.
All that information meets up in a part of the brain called the insula, which figures out the flavor that you’ve tasted. The insula’s conclusion is then routed to emotional centers in the brain—the temporal lobe and the cingulate gyrus—and from there to the orbitofrontal cortex in the brain’s frontal lobe, right above the eyes. That’s the part of the brain that evaluates the experience, and decides whether the meatloaf special at your local diner hits the spot, or not.
There was a time when scientists figured that flavor and aroma were pretty much what determined how we perceived that foods tasted. But in recent years, they’ve developed a more complex model, in which sight and touch are also involved. “The sum total of these signals, plus our emotions and past experiences, result in perception of flavors, and determine whether we like or dislike specific foods," food researcher Terry E. Acree explained in a speech at the American Chemical Society’s convention in 2013.
Your eyes, for example, have a very powerful influence on taste. Your brain’s lateral geniculate body and primary visual cortex are activated by bold, bright colors, which is why colorful foods tend to be appealing. Researchers have found that people associate taste with color so closely than when they gave subjects glasses of Sauvignon Blanc, a white wine, that were tinted deep red to look like merlot or cabernet, they reported tasting the red wines instead of the actual white.
There’s also a feedback loop at work, involving the chemicals in the food that you eat. Consuming sugar, for example, leads to a release of dopamine in the nucleus accumbens, the pleasure center of your brain. Carbohydrates boost levels of the brain chemical serotonin, in the same way that antidepressant medications do.
Similarly, your brain is hard-wired to spot things that taste terrible, and take action to avoid them by sending out an alarm and activates defense mechanisms, such as the gag reflex or a sudden loss of appetite.
The Evolution of Eating
We’re born with certain taste preferences. Research shows, for example, that newborn infants can differentiate between the degrees of sweetness in various solutions, and will consume more of a liquid if it’s sweeter. And from an early age we have an aversion to bitter-tasting substances, which a study published in 2013 in Molecular Biology and Evolution traces back 1.1 million years to a genetic variation in early humans in East Africa.
Scientists believe that those tastes developed because they gave our ancestors an evolutionary advantage. “The ability to taste food is a life-and-death matter,” nutrition researcher Jane Bradbury explained in a 2004 PLOS ONE article. “Failure to recognize food with a high enough caloric content could mean a slow death from malnutrition. Failure to detect a poison could result in near-instant expiration.”
It makes sense, when you think about it. An ancestor of yours with a sweet tooth, for example, was more likely to eat ripe fruits loaded with sugar, which in turn gave him more energy to use when he needed to run away from a predator or root through the bushes for berries. And his aversion to bitter-tasting stuff kept him from eating foods that would make him sick, such as toxic plants and rotting food rife with pathogens. The ability to taste salt and sourness, similarly, helped early humans to maintain their chemical balance, and umami attracted them to protein-rich foods. Our sensitivity to the texture of food also has an evolutionary explanation, because it provides an important indicator of whether or not a food contains fat, which can provide both energy and essential fatty acids.
There’s additional evidence that variations in human taste were evolutionary responses to specific environments as well. Europeans, for example, tend to have a genetic makeup that enables them to taste trace levels of sweetness, while some Africans have a low-sensitivity variation of the gene instead. Scientists believe that difference may have enabled humans living outside the tropics, where sweet fruits and vegetables weren’t as readily available, to enjoy eating the starchier foods that were available there. As Paul Breslin, a biologist at Monell Chemical Senses Center in Philadelphia, explained to ABC News in 2009: "Maybe someone who couldn't detect sweetness very well would never realize that a carrot or a parsnip was something that was nutritious or yummy to eat because it wouldn't taste very good."
How Your Appetite Gets Fooled
In today’s sophisticated civilization, where we can get all the food we need in stores and restaurants, what we eat—and how much of it we consume—often has more to do with tricks that marketers play upon our brains.
Packaging, for example, plays a surprising role in triggering our appetites. Since our brain’s visual centers like bright colors such as red and yellow, marketers tend to rely upon those colors.
When we see food in commercials or in pictures on restaurant menus and supermarket packages, it usually looks really appealing—even more so that the real items actually look once they’re on our plates. That’s because food photographers employ stylists who tinker with food items in myriad ways to make them look more appetizing, from painting on grill marks and applying condiments artfully with syringes, to even gluing on sesame seeds.
The people who want to sell us food also know how to appeal to our evolutionary craving for fats, carbohydrates and sugars. That’s one reason that we’re one of the few species on Earth that overeats. In the U.S., our eating is clearly out of control. Judging from the Body Mass Index—a measure based upon weight relative to height --69 percent of adults age 20 and older are overweight, and 35 percent of them are obese, according to the federal Centers for Disease Control and Prevention. (As an example, a typical man who stands 5’10” would be overweight at 174 pounds and obese at 209 pounds or more.)
Gaining weight, in turn, actually can affect our sense of taste. In a study published in PLOS ONE in 2013, University of Buffalo researchers found that obese mice lost some of their ability to detect sweetness—which, in turn, probably caused them to eat more than their slimmer counterparts.
But it’s also possible for us to override our innate preferences. Despite their genetically-driven aversion to bitterness, for example, humans readily consume coffee, because it contains the pleasurable stimulant caffeine. And young British consumers have learned to associate vivid blue—not normally considered appetizing—with the appealing raspberry-flavor of Cool Blue Gatorade. It’s even possible to retrain our taste to enjoy foods that are good for us, a topic that we’ll get into in the sidebar.
- Answer: Fish
- Answer: 20%
- Low blood sugar
- High blood pressure
- Lactic acid overload
- Hedonic hunger
- Answer: Hedonic hunger
How To Hack Your Nutritional Preferences
Learning to turn down marketing objectives and turn up your health.
In the “How Your Body Perceives Food” article above, we learned that while our taste buds and noses sense flavors, the sensation of taste is actually a complex phenomenon that occurs largely in our brains, and has been shaped by evolution. Our cravings for sweet foods, fat and saltiness—as well as our aversion to bitter tastes—all enhanced the survival chances of our ancient ancestors. But those same tendencies today are exploited by marketers to convince us to eat large quantities of foods that many not necessarily be good for us. Fortunately, however, it’s possible to hack your sense of taste, and retrain it to favor healthier nutrition. Here are some tips.
Mix nutritious items with flavorful ones. Amy Fleming, a food writer for the Guardian, recommends adding ingredients to nourishing but not-particularly-good-tasting foods. She notes that she used to avoid eating kale, a vegetable loaded with nutrients such as vitamin A and fiber, until she started mixing it in with garlic, chili, parmesan cheese, lime, anchovies and pasta. To start loving a healthy food, she writes, "all you need is the right recipe."
Use smaller plates, bowls and glasses. The U.S. Department of Agriculture recommends this trick for fooling your eyes into thinking that you’re consuming a bigger portion than you actually are.
To reduce the amount of sugar, cut down on salt. Yale-Griffin Prevention Research Center director Dr. David Katz suggests that when you bake cookies, leave out the salt in the recipe, and use half sugar. You’ll still find that the cookies still taste just as sweet, because saltiness won’t cancel out some of the sweetness. And you’ll reduce the amount of sodium in your diet, which if it’s too high can have a dangerous effect upon your blood pressure.