In the six-and-one-half years since the federal government began certifying food as “organic,” Americans have taken to the idea with considerable enthusiasm. Sales have at least doubled, and three-quarters of the nation’s grocery stores now carry at least some organic food. A Harris poll in October 2007 found that about 30 percent of Americans buy organic food at least on occasion, and most think it is safer, better for the environment and healthier.

“People believe it must be better for you if it’s organic,” says Phil Howard, an assistant professor of community, food and agriculture at Michigan State University.

So I discovered on a recent book tour around the United States and Canada.

No matter how carefully I avoided using the word “organic” when I spoke to groups of food enthusiasts about how to eat better, someone in the audience would inevitably ask, “What if I can’t afford to buy organic food?” It seems to have become the magic cure-all, synonymous with eating well, healthfully, sanely, even ethically.

But eating “organic” offers no guarantee of any of that. And the truth is that most Americans eat so badly  we get 7 percent of our calories from soft drinks, more than we do from vegetables; the top food group by caloric intake is “sweets”; and one-third of nation’s adults are now obese  that the organic question is a secondary one. It’s not unimportant, but it’s not the primary issue in the way Americans eat.