Organic. GMO-free. Natural. These are so-called health food buzzwords — we read them on food packaging and feel reassured. This food must be healthy. This food must be good for us.

But one of these words is not like the others.

While “organic” and “GMO-free” both have corresponding definitions that provide a description of what these words stand for, the word “natural” is a little more ambiguous.

Although it conjures up images of fresh fruit and green vegetable gardens, “natural” can mean close to anything. The Food and Drug Administration has refrained from developing a concrete definition for the use of the word “natural” or any of its derivatives, allowing food companies to label various products with the descriptor.

And business is booming.

The word “natural” helps companies sell 40 billion dollars’ worth of food in the United States every year. Because the label is so vague, companies can put it on just about anything — as long as the food in question does not contain added color, artificial flavors or synthetic substances.

But that still leaves a broad range of other ingredients available, such as genetically modified and highly processed foods.

Of course, “natural” isn’t the only unclear term out there — companies are moving toward descriptors such as “pure” and “simple,” words that could mean almost anything in a food context, but somehow manage to denote healthfulness. We want to feel like what we’re eating is healthy, and an assurance from a food label — no matter how vague — is usually enough to do the trick.

It’s hard to give every food you buy at the grocery store the third degree. That would be a little time-consuming. Nowadays, simply trying to eat healthy is half the battle — the other half is recognizing that a “natural” chocolate-chip cookie is, at the end of the day, still a cookie.