DEAR DR. BLONZ: Soon after eating something sweet or starchy, I become a bit groggy with an urge to doze off. When out, I can fight it, but sometimes I get nervous and shaky. A friend said that I might have “reactive hypoglycemia,” but I thought those theories were discounted decades ago. -- S.T., Oakland, California

DEAR S.T.: Sugars and other carbohydrates are a source of energy for the body, but they can also be associated with drowsiness, and even, ironically, with the shakiness you describe. One possible explanation is the way simple sugars affect the body and the brain, coupled with inadvertent miscues we give the body through the way we eat.

The body needs to maintain its blood glucose level within narrow limits to keep metabolism on an even keel. Multiple systems kick into gear if glucose gets too high or too low. All the digestible carbohydrates we eat are broken down to simpler sugars, and most end up as glucose in the blood. If it’s from a balanced meal, glucose will rise at a moderate level, but the rise can be rapid if the glucose comes from sweets or a can of soda -- especially if consumed on an empty stomach.

Rising blood glucose is the “I am fed” signal; this then causes insulin to be released by the pancreas. Insulin is the hormone that facilitates the exit of glucose from the blood into the cells, where it provides energy to perform work, build new tissue or create needed substances. A potential connection with drowsiness is the fact that elevating blood glucose and insulin release is paired with the production of relaxation-inducing substances in the brain. (This helps explain the urge to “veg” after a big meal.) The situation becomes more complex in those with Type 2 diabetes, as there can be “insulin resistance” where normal levels of insulin are unable to produce the needed blood-glucose-lowering effect.

You mentioned reactive hypoglycemia, which, although not as common as it was once thought, can develop in some individuals. Reactive hypoglycemia occurs when the body releases too much insulin for a given amount of glucose in the bloodstream.

When blood glucose drops too low, a defense mechanism gets triggered. A hormone involved in this process is adrenaline: the body’s “fight or flight” hormone. Aside from helping provide a small amount of glucose (stored in the liver), adrenaline also revs up the body’s muscles and gets them ready for action. Under the influence of adrenaline, you can feel your heart -- a muscle -- pounding in your chest as it pushes blood into the working muscles to prepare them for action. It is not a pleasant sensation, and the nervousness and shakes you mention could be connected to this phenomenon.

You don’t say much about your general health. I have tried to outline some basic issues, but one certainty is that you need to contact a medical doctor to find out what is going on in your body. There are tests that can provide answers, and it is in your best interest to find out ASAP.

In the meantime, try to stay off the sweet stuff -- especially on an empty stomach.

Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.

DEAR DR. BLONZ: I am not very active and do not eat enough fruits and vegetables, so I have tried taking a powdered wheatgrass supplement product for a few months to cover my bases. Is this the best thing to take as a fix for my situation? -- S.T., Casa Grande, Arizona

DEAR S.T.: The product you are referring to is a powder made from dehydrated wheatgrass. It, and other products like it, supplies a modicum of nutrients and a bevy of healthful phytochemicals.

Aside from testimonials, there is little peer-reviewed scientific evidence to support any health benefits to such a supplement. As would be expected, it has a “grassy” taste, but it certainly won’t hurt you. Assuming the company follows good manufacturing processes, I have no problem with dehydrated greens or other such dried-food dietary supplements. The only people who need to be cautious are those with wheat or grass-related allergies.

That being said, such supplements should not be thought of as a substitute for good eating. You need to rethink your complacency with the “I do not eat enough produce” stance. I would guess that you already know that healthful foods, along with regular physical activity, are the way to go. It is not that hard to get on track; it’s all a matter of priorities. Consider it an investment -- one with a science-grounded, long-term payoff you will realize as the years pass.

Pardon the blatant sermonizing, but a wheatgrass supplement is not a fix. The effects of our day-to-day decisions are often subtle and unnoticed, whether beneficial or negative. Chronic diseases, such as heart disease and certain cancers, are cumulative affairs; the manifestations don’t come to the fore until the disease process has been ongoing for years, if not decades. Taking care of yourself increases the odds that your body will be better able to fend off ill health and chronic ailments.

Put simply, there is no evidence that wheatgrass, or any other supplement, would be sufficient to counter the tide of an ongoing unhealthful diet and lifestyle.

DEAR DR. BLONZ: I was hoping to get your opinion on the safety of drinking Kava, a brand of “acid-neutralized” instant coffee. I read mixed safety reviews online. -- D.K.

DEAR D.K.: The information you found on the internet was likely a mix of details about the coffee brand (Kava) and a similarly named tropical herb (kava, or kava-kava). The herb, scientific name Piper methysticum, is associated with liver damage.

I know of nothing wrong with, or dangerous about, the reduced-acid Kava coffee. In this product, the acid normally present in coffee is neutralized by a potassium compound (potassium hydroxide), so it will contain more potassium than regular coffees. Those who need to avoid too much potassium would therefore be wise to rethink this brand, but that is about the only issue.

Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.

DEAR DR. BLONZ: As a middle school teacher, I am concerned by what many parents give their children for lunch. I want to develop a lesson strategy that involves sending home a newsletter to the parents. Our children’s dietary habits are at stake here, and I do not wish to be a part of the demise of wholesome, nutritious habits. -- F.T., Chicago

DEAR F.T.: A balanced meal, even if processed, is better than no meal at all, or one based on snack foods. But it’s not the foundation on which long-term healthy eating habits are established. One problem with prepackaged, processed foods is that it’s often the foods’ convenience, not their nutrition, that sells them. Consider also that the value of whole foods is greater than the sum of their “nutrient” parts.

The Nutrition Facts label lists calories, protein, fat, carbohydrate and a selection of vitamins and minerals. You won’t, however, find any notation for the healthful phytochemicals found in fruits, vegetables and whole grains. A fabricated, fortified food could wear the same Nutrition Facts label as a whole food where these nutrients occur naturally with all their associated healthful compounds, but it would not truly be as healthful.

Lessons and a newsletter are great ideas, but I would proceed cautiously. The idea is to enlist the support of the parents -- not alienate them.

In the classroom, gather a list from the children of their favorite processed foods, and then find and present the ingredient lists of those foods. Go through the ingredients, explaining which are true “food,” which are good for you and in what ways, etc. You will have to do some online research on food ingredients. The lesson can be an eye-opening exercise, and it can be made quite entertaining. The idea is to give the children important facts, empowering them to go home and begin using their new knowledge on their next shopping trips and while checking the foods in their pantries.

At home, it’s important to get children involved in menu planning. Parents should discuss food options and ask for input. If there is more than one child, they should take turns. If possible, take them along on shopping trips to increase the odds that they’ll eat fruits and vegetables that they select.

At the grocery store, a child is at the receiving end of a tremendous effort devoted to influencing their minds and their parents’ shopping behavior. This effort goes hand in hand with the highly produced advertisements clustered around children’s television shows. Therefore, it’s best not to have children go shopping on an empty stomach. Parents should plan ahead about how they’ll react when their child bargains for dubious items. Depending on past experiences, it may be helpful to go over basic ground rules before entering the store.

Parents also need to enlist their children’s help with meal preparation. Being involved before the meal can increase satisfaction with what’s to come, whether it’s making a lunchtime sandwich, helping measure ingredients or simply arranging food on a serving plate.

All these efforts can have a greater chance of success if paired with ongoing, in-school lessons about the value of wholesome, healthful foods and their importance to growth and good health. I applaud your energy and wish you well in your efforts. I wrote a Supermarket Buying Guide for the Berkeley Wellness Letter to help with these types of issues, and it is available at no charge online: goo.gl/1pOkw9.

Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.