Structure can be a student's greatest ally.

Because of this, there's a designated spot on my chalkboard where all homework is listed every day. I begin class by referring to the list and frequently end class by saying, "Don't leave the room unless you're sure how to do the assignment."

Despite these daily routines, I've been hearing this declaration more and more over the last few years: "I didn't know we had homework."

To that, I nod, point to the assignment written on the chalkboard, and wait for the when-did-you-write-that? look to appear upon the speaker's face. The look, more often than not, seems genuine.

Keep that reaction in mind as I explain another in-class occurrence happening far more than before. "Raise your hand to speak and wait to be called on," is a constantly repeated and reinforced rule in my school, but often as I'm answering a question that requires more than a single sentence explanation, a student interrupts.

Yet rarely is it a calculated attempt to disrupt.

Sometimes the offender wants to provide the rest of the answer; sometimes he asks a totally unrelated question. Sometimes the interruption actually comes from the student who asked the question.

Sometimes there are so many interruptions in such a short span that I'll eyeball the last interrupter and ask, "Would it be possible for me to finish at least one sentence on my own today?" More often than not, a did-I-interrupt-again? look flashes across the last interrupter's face.

And, more often than not, the look seems genuine.

So what's happening here? Am I being conned by kids clever enough to feign surprise when they interrupt or forget homework?

I don't think so.

Something else is at work here. Something that causes some students who want to follow classroom rules and do homework not to do so at least some of the time.

That's why I was not surprised when a November issue of the Center for Disease Control's Morbidity and Mortality Weekly Report showed a 21.8 percent increase in the diagnosed cases of attention-deficit/hyperactivity disorder (ADHD) between 2003 and 2007 for children between the ages of four and 17.

That's a jump in four years from slightly more than one out of every 12 to nearly one in 10. If the increase has continued to the present, the ratio is now close to one out of every eight quite a rapid rise for a syndrome that was only first recognized in 1987.

And a frightening one, considering genetics only accounts for about a fifth of the increase.

One ADHD online support group, ADHD.org.nz, relates that about half of all ADHD cases can be explained by genetics. Since the population of the United States in the last decade has increased by 9.7 percent, you would expect the diagnosed cases of ADHD with a genetic base to increase by 4.85 percent over that same period, not 21.8 percent in just 40 percent of the time.

Other factors have to be increasing the rate. ADHD.org.nz claims that smoking during pregnancy increases the likelihood since studies have shown that mothers who don't smoke during pregnancy are less likely to have babies with learning disabilities and/or hyperactivity.

But the rate of smoking in the U.S. has remained relatively stable, so that can't be the cause for the increase.

ADHD.org.nz also lists 10 possible "causal agents" that may very well increase the rate of ADHD. Four of them sugar, caffeine, food colorings, or the lack of Omega-3 essential fatty acids are directly related to diet.

Could bad eating habits keep young brains from functioning productively?

Carol Simontacchi, a certified clinical nutritionist and author of the provocative book, The Crazy Makers, thinks so. In the aforementioned book, she argues that years of eating what she calls "pseudo-foods" has not only rewired our brains but also eroded our minds.

In fact, Simontacchi concretely links bad diet to the fact that "nearly one in two adults [now] experiences a mental disorder at some point in life" and states that "pseudo-foods" are at least to some degree responsible for the marked increase in ADHD.

The Crazy Makers was published in 2000, years before the reported increase in ADHD that spurred this article. Since then, our use of pseudo-foods has increased, strengthening the argument that kids don't have to inherit ADHD through genetic transmission for their parents to be culpable.

A diet highly reliant on overly processed grocery items and frequent meals from fast-food restaurants definitely contains an excess of sugar and food colorings, probably contains too much caffeine (especially for a teen or preteen), and can't provide the needed amount of Omega-3 essential fatty acid a fat found in its greatest amounts in wild fish, to a lesser degree in wild game, but in minute amounts in mass-produced animals fattened on grains.

This alone should be motivation enough for parents to wean their kids away from junk food, but new research has provided something else. While many children who develop ADHD grow out of it by the time they are adults (though there has been an increase in adult ADHD as well), research done at Duke University shows having ADHD as a teen increases the likelihood of becoming obese as an adult.