In the last column, I suggested parents should have a conversation with their kids explaining the differences between a "good snack" and a "bad snack" as a way to make the snacking that kids do and should do help rather than hurt overall health.

The creation of such a column was a direct result of troubling research. A study in the March issue of the journal Health Affairs showed that while children ages 2-18 in 2006 averaged fewer calories from meals than in 1977, total calories consumed were up by 100 per day.That's because the frequency and the size of snacks have increased to such an extent that kids are now eating 700 extra calories a week, an excess that if not balanced by additional exercise could result in a weight gain of more than 10 pounds per year.One solution is to have parents restrict the number of snacks, but the best one is to simply make snacks healthier.While doing so will significantly improve health, it's important not to see healthier snacks as the be-all and the end-all. After all, the study in Health Affairs did establish that more than 70 percent of a typical child's daily caloric intake comes from breakfast, lunch and supper.Because carbohydrates generally account for more than half of all calories consumed , it's essential that parents tell children the "good carb/bad carb" story. I say "essential" not to be melodramatic but to recognize the way the world has changed.Many children today eat most of their meals without mom or dad present; many children in prior generations did not.For instance, I ate nearly every meal every day with at least one parent present up until sixth grade. That was possible since my mother had decided to work nights until her boys were grown and our elementary school permitted students to walk home for lunch.Because mom was always present, she decided what were "good carbs" and "bad carbs" for me. My clearest memory of this comes from our twice-a-month trips to a restaurant (every Friday that my father got paid) and hearing mother exclaim, "Don't you dare take a second bun from that basket!"There was no food I loved more than a hot bun oozing with butter back then. I would've eaten three or four if mom would've let me. (In fact, I did that a few times when I went out to eat with only grandma.)While mom didn't give me the "good carb/bad carb" speech back then she erroneously believed all "starches" eaten in excess immediately became fat she did clearly establish rules and a link between what I ate and how I felt and looked. That's what parents should hope to achieve by a discussion of "good carbs" and "bad carbs": not only rules, but also the planting of a seed, the notion that mood and body shape are to some degree controlled by you through what you eat.Now, if you're sold on the need for the "good carb/bad carb" talk, but are a little bit confused about how to clearly delineate between the two, here's what you need to know.Carbohydrates are called simple or complex based on their chemical structure. Although both can be used as energy by being transformed into glucose (blood sugar), there are significant differences that make receiving your energy from complex carbs preferable.Because their chemical structure is simple, simple carbohydrates digest more quickly than complex carbs as well as protein and fat. As a result, more than the needed amount of glucose often enters the bloodstream, which causes more than the needed amount of insulin to be secreted.Insulin is the storage hormone, so it extracts the glucose from the bloodstream and escorts it to the muscle cells. Unfortunately, muscle cells don't have much storage capacity and prefer energy derived from complex carbs; therefore, much of the glucose is turned away.It's not returned to the bloodstream, however. Insulin escorts the glucose to the fat stores where it is readily accepted.This deposit provides a double whammy. Not only does it increase the fat stores but the lack of glucose in the bloodstream also creates a sensation of hunger.That's right. Even though you have just eaten and stored away fat for use as future energy, you get a sensation of hunger.If you foolishly fight the hunger with another dose of simple carbohydrates, the entire process begins again. Overeating simple carbohydrates is why someone can eat a substantial amount of calories, complain of being hungry about 90 minutes later, and not be lying.But if you originally choose complex carbohydrates, the complex chemical structure of the food including the presence of fiber delays digestion. Glucose enters the bloodstream incrementally, which means less insulin is secreted.Because of this, more glucose remains in the bloodstream, and because the insulin now escorts a more preferable energy source to the muscle cells and less of it the cells are more likely to accept the energy. Furthermore, complex carbs do not get stored as fat as readily as simple carbs.Energy is wasted in the transformation. This waste means there's less to store, and less weight gain.That's why kids and adults alike should view an overuse of processed snack foods, fast foods, white breads, sodas, fruit juices, and even milk products and fruit as "bad," and the liberal use of vegetables, whole wheat and whole grain products, and legumes as "good."