10/23/2008 05:12 am ET | Updated May 25, 2011

What You Don't Know About Your Tongue Might Be Making You Fat

I learned a new word the other day: umami. It's something I have on my tongue, even though I didn't know it. You have it, too. Common knowledge has it that our tongues have receptors for sensing four things: bitter, salty, sour, and sweet. But it turns out that we also sense umami, and that, to the human palate, umami is far and away more pleasing than the other four sensations. Hitting our umami sensor will make all kinds of bells and whistles go off in our brains. The person who first figured this out was Japanese, and he coined the term. Umami is the Japanese word for "yumminess", and it describes a hearty, deeply satisfying taste sensation, the kind you might get from eating a steak.

Even though I didn't know I could sense "yumminess" with my tongue, there are people out there who have known for a long time: food scientists and corporate food conglomerates. Food scientists are the chefs of the supermarket shelves, even when there's an actual chef's name on a product. It turns out they're pretty clever at making products that will satisfy the "yumminess" sensation we're wired to love. Interestingly, ketchup (along with soy sauce) is a product that manages to hit all the taste receptors on the tongue. It's a rock star food product, which kids seem to have instinctively figured out.

Scientifically, what we're tasting when we taste umami is glutamic acid, an amino acid also known as glutamate (yes, glutamate, the G in the notorious MSG), which occurs naturally in foods, but is in highest concentrations in meats, chicken, fish, cheese, and other high protein foods. When you season a steak with salt and pepper, grill it, and enjoy the deliciousness, what's making it so delicious is all that naturally occurring glutamate. That's umami as humans have enjoyed it since the beginning of time -- or at least since the discovery of fire. But when you heat a frozen prepared entrée that lists as one of it's ingredients "natural flavors," chances are you are eating something with some form of added glutamate, a food scientist's manipulation of your perception of yumminess. With the large batch cooking, packaging, and transport, factory-made food cannot compare in taste to homemade. To make up the flavor difference they add "natural flavoring" until they achieve umami. These "natural flavorings" are there to stimulate your tongue; other than that they have no nutritional value whatsoever.

It has always astonished me that, with the large amount of prepared and shelf-stable food, the FDA does not demand that companies disclose the names and provenance of "natural flavorings". The word "natural" is a subversive stretch; my guess is that to most laymen, and actual chefs, natural flavorings wouldn't sound very natural.

In the U.S., take-out food and restaurant dining, much of it in corporate chain restaurants, accounts for 50% of consumer food dollars. That means that a lot of what we're eating is food that's been manufactured in a factory (see my June 10 blog entitled "The Death of the American Chef") and tweaked by food scientists, using "natural flavorings" as flavor enhancers to intensify it's yumminess.

What does this all have to do with making you fat? The vast majority of us are overweight, and food is a drug to most obese people. It brings happiness and temporarily dulls the pain. Manipulation of our food -- the drug of choice for many of us -- so that it has, unbeknownst to us, enhanced appeal to our biology, sounds like something out of science fiction. Our government has an obligation to hold food companies accountable for specifics of the "natural flavors" that are added to so much of our food.

There are many reasons to avoid conventionally prepared, corporate food products. Keeping your sense of yumminess truly natural is just another reason to add to the list.