How Flavor Drives Nutrition

How Flavor Drives Nutrition

For more than 50 years, our food has been getting blander—but the best diets turn out to also be delicious

By Mark Schatzker in the Wall Street Journal

For nearly a half century, America has been on a witch hunt to find the ingredient that is making us fat. In the 1980s, the culprit was fat itself. Next it was carbs. Today, sugar is the enemy—unless you’re caught up in the war on gluten.

And none of it has worked. Obesity is now closing in on smoking as our No. 1 preventable cause of death. The U.S. has rarely failed at anything the way it has failed at weight loss.

Perhaps that is because we’re missing a crucial piece of the food puzzle. Oddly enough, all those diet gurus and bureaucrats hardly ever ask the simplest question: How does it taste? We’ve fixated on what food does inside the body, but we’ve almost totally ignored why it gets there in the first place. Even a child knows: We eat because food is delicious.

We have been trained to see this as a bad thing. After all, if food weren’t so appetizing, we wouldn’t eat so much of it. But the human body takes flavor very seriously. Our flavor-sensing equipment occupies more DNA than any other bodily system. If deliciousness is our enemy, why are we programmed to seek it out?

Every other animal depends on taste and smell to identify nutrients crucial to life. Insects use flavor chemicals to distinguish between food and poison. Diabetic lab rats instinctively avoid carbs. Sheep who are deficient in essential minerals, such as calcium or phosphorus, will crave flavors associated with them. And monkeys infected with gut parasites will eat specific leaves that alleviate their conditions. “Flavor,” says Fred Provenza, a behavioral ecologist and professor emeritus at Utah State University, “is the body’s way of identifying important nutrients and remembering what foods they come from.”

Humans are no different. In the 18th century, sailors ravaged by scurvy were gripped by intense longings for fruits and vegetables. Pregnant women are nauseated by foods that their bodies perceive as toxic.

But perhaps the most striking proof of such nutritional wisdom comes from a 1939 study in which a group of toddlers were put in charge of feeding themselves. They were offered 34 nutritionally diverse whole foods, including water, potatoes, beef, bone jelly, carrots, chicken, grains, bananas and milk. What each child ate, and how much, was entirely up to him or her.

The results were astonishing. Instead of binging on the sweetest foods, the toddlers were drawn to the foods that best nourished them. They ate more protein during growth spurts and more carbs and fat during periods of peak activity. After an outbreak of mononucleosis, curiously, they consumed more raw beef, carrots and beets. One child with a severe vitamin D deficiency even drank cod liver oil of his own volition until he was cured. By the end of the experiment, one doctor was so impressed with the toddlers’ health that he described them as “the finest group of specimens” he’d ever seen in their age group.

These toddlers knew nothing about carbs, fat or gluten. They just ate what tasted good to them.

A 2006 paper in the journal Science shed light on the chemistry underlying those flavor cravings. Scientists Stephen Goff and Harry Klee discovered that the 20 most important flavor compounds in tomatoes are all synthesized from important nutrients, such as omega-3 fats and essential amino acids. In other words, what makes a tomato nutritious also makes it delicious. This undeniable link, they wrote, suggests that flavor compounds “provide important information about the nutritional makeup of foods.”

So what makes toddlers in the 1930s different from children today? Why could Americans stop themselves from overeating in the 1960s, and why can’t we stop stuffing ourselves today?

Our relationship to flavor hasn’t changed, but flavor’s relationship to food has.

For more than 50 years, the food that we grow has been getting blander. As our crops and livestock become more productive, affordable and disease-resistant, they keep losing flavor. As any grandparent can tell you, tomatoes, strawberries, chicken—all taste like cardboard these days.

As flavor diminishes, so does nutrition. According to a 2004 study in the Journal of the American College of Nutrition, modern tomatoes have half as much calcium and vitamin A as they did in the 1950s. We compound the nutritional insult by drowning bland food in the only things that can make it taste good—ranch dressing, whipped cream, ketchup or barbecue sauce.

And in the modern food system’s most disturbing twist, we now take the very flavors that are disappearing on the farm and produce them in factories, sprinkling them on potato chips or fizzing them into soft drinks. Today’s junk-food aisle is overflowing with the very flavors—cherry, blueberry, tomato, strawberry—that have gone missing in the produce aisle.

While the U.S. government has busied itself with promulgating pictures of food pyramids, Americans have been consuming more than 600 million pounds of synthetic flavorings a year, according to Euromonitor International, a London-based market-research firm. And don’t be fooled by FDA-sanctioned wording: Those “natural flavors” are every bit as synthetic as “artificial flavors.” The difference refers to how they were made, not what they are.

Much of the food that we now eat is, on a sensory level, telling us lies. A “strawberry-flavored” yogurt may taste wonderful to a two-year-old, but it doesn’t carry anything close to the payload of vitamins, minerals and antioxidants in a real strawberry. We have short-circuited the age-old system of flavor.

Flavor also lights the path forward. If the federal government really wants to tell people what to eat, here’s some sound advice it could offer: Eat food that tastes better. Don’t ignore your cravings. Don’t deceive yourself with fake flavors. Instead, satisfy your desires with real food that is genuinely delicious. Approach each meal like an Italian chef obsessed with finding the best, freshest ingredients. The more you let flavor and pleasure be your guide, the better your eating choices will be.

A 2006 study of more than 3 million supermarket receipts from 98 supermarkets in Denmark found that Danish shoppers who purchased wine also bought healthier options across the board—olives, fruits and vegetables, spices, tea—instead of ketchup, chips, soda or precooked meals. The good health of wine drinkers may not be due to some artery-cleansing compound in grape skins; it may be because those who like the taste of wine also like the taste of healthier food. Similarly, Dr. Klee found that “foodies” were turned on by the flavor compounds in tomatoes—compounds linked to essential nutrients. Non-foodies were more turned on by sugar.

The lesson: Spend money on the good stuff. Vote for real flavor with your pocketbook, and let the free market work. Remember what buying wine and beer was like before Americans took them seriously? Now imagine what the supermarket might look like if we took flavor seriously. Stop counting carbs. Don’t live in fear of fat. Start eating food that tastes better. We’ll all be skinnier, healthier and a whole lot happier.

— Mr. Schatzker’s new book, “The Dorito Effect: The Surprising New Truth About Food and Flavor,” will be published by Simon & Schuster on May 5.