DEAR DR. BLONZ: I have an allergy to crab and lobster, due to the iodine. Shrimp doesn't bother me at all, but my big question is whether scallops fall into the crab/lobster category or into the shrimp category. I have wanted to enjoy these tender morsels for a long time, but am cautious, due to my fears of a potential heart-stopping reaction. -- J.B. Seattle, Washington

DEAR J.B.: The typical shellfish allergy is not due to the presence of iodine. Some people may react to iodine, but usually only when there is inadvertent exposure to large amounts, such as with a disinfectant used in surgery or other medical procedures. Iodine is an essential mineral needed by the body to synthesize its thyroid hormone, which is involved with the regulation of our metabolism. This mineral is found in most seafood, but it is also present in foods made with iodized salt -- including most foods served in restaurants.

When there is insufficient iodine, the thyroid gland, which is located in the throat, becomes enlarged and the condition referred to as "goiter" results. Goiter used to be common in the Great Lakes regions of the United States, but the condition was virtually eliminated following the addition of iodine to table salt in 1924.

Shellfish allergies tend to relate to a sensitivity to the protein found in shellfish. The shellfish family includes clams, crabs, lobsters, oysters, shrimp and scallops. Specific food allergies are possible, but it is unusual that one would be able to tolerate shrimp when crab and lobster set them off. Because scallops are in the shellfish group, it would be best to refrain from any experimentation -- especially if there is a risk of a "heart-stopping" reaction. The prudent approach would be to consult with an M.D. allergist. He or she can determine if it would be appropriate to give you an allergy test where you'd be exposed to very dilute extracts of the fish in a controlled, safe setting. Stay well.

DEAR DR. BLONZ: I am seeing a holistic medical doctor who relies heavily on a technique called "muscle testing" to determine which nutritional supplements I should be taking. The supplements are placed under my tongue, and then, while I am on my back, he has me raise my right leg about 10 inches (while the pill is still under my tongue). If he can press my leg down, he recommends that supplement be taken. If he cannot force my leg back down on the table, he says I don't need the supplement. What is your opinion of this technique? -- C.B., Los Angeles

DEAR C.B.: This test is dubious, to say the least. I have never found any evidence to support the reliability of such a technique. If it were me, I would find another doctor.

Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 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 have concerns about my son's coach asking his athletes to eat a great deal of protein, as much as 18 eggs a day (yolks and all), to gain more muscle weight. I have been unable to find any information concerning any research or studies showing that that much additional protein will have the desired effect on muscle weight. -- B.B., via email

DEAR B.B.: Protein is key to our health, but this recommendation is ill-conceived and illogical. If you want to gain weight, there are better ways, including eating more often (at least six meals a day) or having additional servings of nutrient-rich/calorie-dense foods. Those that come to mind include nuts, seeds, avocados, etc. The other essential adjunct is a structured training program designed to make the body increase its muscle mass.

Eggs are not a calorie-dense food -- they provide high-quality protein, but they are not an ideal food to overload to the extent the coach recommends. Eighteen large eggs will provide 1,350 calories, 112 grams of protein, 90 grams of fat and 3,825 milligrams of cholesterol! That is way too much cholesterol -- even for a high school student. And what else are you supposed to eat during the day? I enjoy eggs, they are great food, but they do not comprise a well-balanced diet in and of themselves.

And while I encourage people to eat food as opposed to supplements, there are a number of concentrated-calorie milkshakes on the market that are targeted for those trying to gain weight. Athletes such as weight lifters, wrestlers and football players often use these products to help them bulk up for their sports. They're ideal for those who are underweight, who have to work at maintaining their weight where it is. Most of these products contain hundreds of calories, and when taken in addition to a regular diet, you will begin to gain weight.

There is also the common-sense directive to stay away from weight gain using junk foods, such as French fries, chips and donuts. This is bad stuff. Going down that road may cause you to gain, but it is likely to impact your quality and length of life well after you take off the uniform.

Understand that there is a limit to what you can do. Then there is the overriding influence of your genetic predisposition. If most family members are smallish and thin, it lessens the odds that you can become a 250-plus-pound player. This is not to say you are without any remedies, but they might not achieve the desired result.

A well-balanced diet in addition to weightlifting and conditioning programs are important adjuncts to any weight-gain program. Consider, though, that if you were to gain 1 pound a week, this would involve taking in an estimated 500 calories a day above a normal caloric intake. Snacking on healthful calorie-dense foods or using those weight-gain milkshake products can help accomplish this. Be advised, though, that studies have found that the body does not always gain as expected. This is why training programs, which involve conditioning and the gaining of weight and muscle mass, are best accomplished as a slow-and-steady process during the offseason, not rushed once the season has begun.

Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 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 have a question about carbohydrates. You have stated that once a carbohydrate is converted to fat, it can never become a carbohydrate again. If glucose is so important to the human body, why have we evolved to store excess energy as fat and not carbohydrate? -- R.D., San Francisco

DEAR R.D.: The human body can't run on batteries, and it has no mechanism for the continuous capture of energy from nonfood external sources, such as the sun, as plants do. Our only sources of energy are the proteins, fats and carbohydrates we eat. And because we are not eating 24/7, there is a need for energy storage.

Fat is the ideal storage substance because it is nature's most concentrated form of metabolic energy. There are approximately 9 calories per gram of fat, compared with 4 calories per gram of protein or carbohydrate. (Alcohol, it turns out, provides 7 calories per gram, which is something those concerned with their body weight should consider.) You find energy stored as fat throughout the animal world, whenever mobility is needed. If we stored the bulk of our energy as carbohydrate, we would be too bulky to move.

This takes on more meaning when we consider plants. By contrast, their basic theme is not mobility: They stay put, sending roots into the soil for water and nutrients, and leaves up to the sun. Plants are able to utilize sunshine directly, converting it into energy for growth and functionality -- including the production of flowers and of seeds for the next generation. As plants take in their "meal" of sunshine, they turn the energy into carbohydrate because it takes up the most space per calorie.

Although the "mission" of the plant is to grow rapidly while remaining in one spot, that of the seed is much different. It must first travel away from the parent plant, being carried by winds or on the fur of animals. In many fruits, the seed is inside a hard-coated pit that is surrounded by tasty flesh that becomes sweet and gives off enticing aromas once the seed is fully developed and ready to go. Animals do the harvesting and rely on the flesh for their own nourishment, and the pit enters their digestive system and gets dropped in a new area where the plant can develop.

Once the seed falls upon a new patch of ground, it must have enough energy to send out roots and produce that first shoot so that it can begin gathering new energy from the sun. The seed, unlike the parent plant, requires an "energy-dense" material so it can be lightweight and compact in size. This explains why in seeds we find energy stored as fat. Nature: fascinating stuff.

Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 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.