DEAR DR. DONOHUE: In an effort to reduce obesity in children, our school removed the soda machines from the cafeteria. The sugar content of most sodas is approximately 28 grams. The bad news is that sodas were replaced by fruit juices that also have a high sugar content.

Should all sugars be treated equally as far as weight gaining goes? – A.K.

ANSWER: Carbohydrates are a class of food and drink that includes sugars and starches. I am aware of the intense focus on low-carbohydrate diets as the answer to obesity, but not all carbohydrates, including sugars, are evil.

The amount of table sugar added to foods should be limited, because pure sugar comes with no nutrients other than calories. Sugar contributes, therefore, to obesity and to tooth decay. All sugars do it.

Many soft drinks are sweetened with high-fructose corn syrup. Fructose is sugar. When it comes packaged in fruit or fruit juice, it is not a problem. High-fructose corn syrup, like table sugar, brings no other nutrients with it besides its calories.

Take orange juice in comparison. Eight ounces of orange juice has 26 grams of fruit sugar – fructose. That’s not much less sugar than the sugar content of pop. But the amount of health in a glass of orange juice is enormous, including vitamin C, vitamin A, folate (a B vitamin), and the minerals potassium and magnesium.

One gram of carbohydrate has 4 calories. (One gram of fat, however, has 9 calories.) There might not be a tremendous reduction in the calorie content of fruit juice compared with pop, but there is a tremendous gain in health benefits.

Getting rid of pop is an attack on the obesity problem, but it cannot be the sole attack. Other foods, particularly fats, must be considered, as must an increase in calorie burning through exercise.

DEAR DR. DONOHUE: About a year ago I had a series of blood tests done. All were normal except for one called CK, which, I understand, indicates muscle disease. My doctor has put me through countless tests to find out why my CK is high. I have also seen three specialists. No answer is forthcoming. I feel fine. I wish I had never taken the damn test. What would you do? – T.C.

ANSWER: CK is creatine kinase, an enzyme found in skeletal muscle, heart muscle and the brain. It’s also known as CPK – creatine phosphokinase. In order not to get bogged down in details, let’s limit this to CK elevations coming from skeletal muscle.

Muscle injury – muscle trauma – elevates blood levels of CK. The injured muscle leaks its CK enzyme into the blood. Muscle illnesses, such as polymyositis and muscular dystrophy, also raise the blood CK level. So do viral muscle infections. Thyroid gland and parathyroid gland problems affect muscles and cause a CK rise.

Your enzyme level has been high for a full year. You feel fine. Four doctors have found nothing wrong with you. All other laboratory tests and investigations have not turned up any problem.

What I would do in a case like yours is declare a truce and lay the issue to rest as a fluke. Your CK level can be rechecked in six months or a year, but beyond that I would call off the search.

DEAR DR. DONOHUE: Twenty-eight years ago, my friend’s son had Rocky Mountain spotted fever. They treated him, and he got better, but they didn’t know if there would be any long-term side effects. For the past five years, his personality has changed for the worse. We wonder if his personality change could be due to the Rocky Mountain spotted fever he had. – L.G.

ANSWER: Rocky Mountain spotted fever causes a rash and an unbearable headache. It can be fatal if antibiotic treatment is not begun quickly. Long-term complications include muscle weakness, hearing loss and difficulty speaking, but those complications almost never happen when treatment is given. And when they do happen, they do so immediately following the illness.

Personality changes years after the infection are not likely due to RMSF.

DEAR DR. DONOHUE: My doctor tells me I have diabetes. You couldn’t prove it to me, because I have never had any diabetes symptoms. It was discovered on a routine blood test. The doctor had me on a diet, but that didn’t lower my blood sugar, so now I am on a tablet. He says that if the tablet doesn’t work I’ll have to take insulin. This sounds like overkill to me. Is it? – M.G.

ANSWER: Diabetes is often discovered in the same way yours was. A routine blood test shows high sugar. The classic diabetes symptoms of unquenchable thirst, the drinking of prodigious volumes of water, the eating of prodigious amounts of food, and the nonstop trips to the bathroom to empty the bladder are often not part of the picture.

Your doctor is not overdoing his insistence on good control of blood sugar. Without meticulous control, diabetics are at high risk for the complications of diabetes. Uncontrolled diabetes is a major risk for a heart attack. If a person has diabetes and high blood pressure, that person has eight times the chance of having a heart attack than does the nondiabetic population. If you add one other factor to the mix, high cholesterol, then the chances of having a heart attack zoom to 20 times that of the general population.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475.