DEAR DR. BLONZ: Our son, now 13, has grown about four inches in the past year. Lately, he has mentioned experiencing some muscular pains when playing soccer, often stating that the soles of his feet hurt. He describes the pain as more annoying than severe. The coach and I have instructed him to stretch and warm up prior to any intense efforts. I feel that he also needs to address other areas, such as nutrition and vitamin and mineral supplementation, especially since he does not eat well. What might you suggest for a child regarding vitamin and mineral supplementation? -- D.J., Walnut Creek, California

DEAR D.J.: Generally speaking, it is not unusual for rapidly growing children to experience minor aches and pains as they mature into their adult body. Discomfort may be caused by muscles and tendons that become too tight for their rapidly growing long bones. These types of "growing pains" are often experienced at night, when most growth occurs, but they can also be felt during the day. (For more on growing pains, see b.link/6tpy7hg.)

You mention pains in your son's foot. Each foot contains 26 separate bones (1/8 the total number in our entire skeleton), and some tendons pass around the ankle to control the movements of the foot. Discuss with the health professional who, ideally, has been tracking his growth over the years, whether his discomfort could be a side effect of his rapid growth. You may learn that stretching before the workout, along with periods of rest during the game, can be beneficial.

And please don't ignore the obvious. I realize that a child's rapidly growing body can run through clothing sizes in a way that sends shivers through one's bank balance, but if not already done, make sure that your son's shoes -- especially his soccer cleats -- fit correctly.

As for your nutrition concerns, any period of rapid growth relies on the creation of new body tissue, and that means an ample supply of raw materials, such as protein and minerals, plus the vitamins and dietary energy (fat and carbohydrate) to keep the process fueled and on an even keel.

Good eating habits are often overlooked during the teenage years. At times, we, as parents, might wonder how our children are able to grow and remain in good health, given what they eat.

There are limits to what a parent can accomplish during their child's adolescence. Playing a parental power card may backfire, as these are the very years when a child feels the drive to establish their independence. One key is to set a good example by what you eat and to keep him involved as much as possible in decisions that relate to food choices and food preparation.

You ask about vitamin and mineral supplements. I believe that food must always be the focus. If you want a supplement, opt for a general, all-purpose multi-vitamin/mineral tablet or powder, with an eye on providing those nutrients that are missing from his daily diet.

Finally, many adolescents take pride in seeing their bodies change and mature. If they can be made to understand the benefits of using healthful, whole foods to provide the raw materials and nutrients the body relies on to build its muscles, bones and skin -- and that this is something over which they have control -- they may be more willing to make improvements.

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: The talk at the gym among my 50-something crowd is that protein needs are especially important for those seeking to build muscle. A popular drink at the cafe has a vitamin and collagen protein powder. It tastes great, but I wanted to know if it makes scientific sense to need a protein drink after a heavy workout. A lunch rides on your answer. -- G.R., New York, New York

DEAR G.R.: Nutrition for athletes has evolved into a distinct branch of science, with its own academic departments, professional organizations and peer-reviewed research journals. It's a far cry from the early days when a thick steak on a football training table marked the limits of nutritional awareness.

The nutrient needs of the athlete can be simplified into two areas: providing the energy (calories) to fuel the activity and the body's post-activity response, and supplying the nutrients and raw materials to build and repair muscles and tissues.

Regarding protein, healthy eating habits that include all essential nutrients can support the requirements of routine exercise. The data suggest that intensive muscle building or endurance events can increase our need for protein.

Normal adult protein requirements are 0.8 grams of protein per kilogram of body weight, per day (0.8g/kg/d), or 11 grams for every 30 pounds of body weight. For older adults, an aging digestive system and some medications increase this to 1.0–1.2 g/kg/d (approximately 15 grams for every 30 pounds of body weight). Athletes and intensely active individuals may benefit from up to 2g/kg/d (27 grams of protein for every 30 pounds). Having more protein than the body needs tends to be the norm in this country. Middle-aged adults consume about 97 grams of protein per day.

While athletes and muscle builders may benefit from more protein on their menu, excess protein has no magical powers to build muscles. When no longer needed as protein, it is broken down for use in other ways, mainly into energy compounds (carbohydrate and fat). That breakdown contributes to dehydration, an increased acid load on the kidneys and a potential loss of mineral elements, such as calcium in the urine. Don't be misled by protein powder supplement claims of dramatic results with alluring pictures of bulging muscles.

Your "50-something" mention also merits caution that an aging body should avoid overdoing exercise. Read about signs that you may be getting too much at b.link/Lp3xfcy. Water intake must also be discussed, as it not only helps keep the body cool through perspiration, but also shuttles waste products from energy metabolism and excess protein breakdown out of the body via the urine. Dehydration, even when mild, impairs performance and can cause the body to overheat. Drinking water is an essential part of any exercise routine.

For athletes and other health-conscious individuals, food remains the best and most readily absorbed source of all nutrients. Those who opt for a balanced and varied selection of protein, complex carbohydrates, fiber and healthy fats from all the food groups will have little difficulty meeting their nutritional needs. So, who's paying for the lunch?

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 recently read an article about the cancer risks associated with cooking food on the grill, but I have always wondered if these same cautions apply to both charcoal and gas BBQs. We are fortunate enough to be able to use our gas grill year-round. -- V.M., Oakland, California

DEAR V.M.: Cancer stems from a "mistake" in a cell's DNA, the inherited genetic blueprint that tells a cell what to do. Substances that alter genes fall into two categories: mutagens cause genetic changes that may or may not lead to cancer; carcinogens alter genes in ways known to cause cancer. While the human immune system is specifically designed to locate and destroy mutagens and cancerous changes before they get the upper hand, they're nothing to be trifled with.

The issues with barbecue or grilling dangers come from two fronts. Heat and flame hitting the food can cause the formation of mutagens. Next, fats dripping on the hot surface can break down into mutagens and carcinogens, which travel back up to the food with the smoke. Given this scenario, it makes little difference whether the heat comes from charcoal, heated lava rock or directly from a gas flame. The adjustable nature of the gas flame might be considered an asset, as it could be modified periodically to prevent flare-ups and ensure an optimum cooking temperature.

Most forms of high-heat cooking can cause changes in food. With grilling, there tends to be more of those changes, so it's prudent to keep your exposure to a minimum. There are also ways to reduce the risk. Here are a few suggestions: Plan ahead, extend cooking times and keep temperatures more moderate by controlling air flow. The lower the heat, the less smoke and charring. You can limit the time spent on the grill -- with minimal impact on flavor -- by pre-cooking foods in a conventional or microwave oven. Other options are to use indirect heat, rather than cooking the food directly over the heat source. You can also have a pan between the food and the flame to catch or divert the drippings before they hit the heat source. Using marinades can also reduce mutagen formation.

That said, occasional grilling, which I enjoy, should not be a source of great concern. It's yet another reason for healthy eating, given that whole plant foods evolved with substances that protect against unwanted cellular changes, and they can work for us as well.

One final perspective: If you are worrying about eating the food on the grill while sitting outside in the sun, unprotected by sunscreen, or are smoking, eating an unhealthy diet, have an inactive, stress-laden lifestyle or drink alcohol to excess, your priorities are all wrong. And keep the kids away from the grill. All things considered, there's a far greater risk of getting burned than getting cancer. For more on the topic, see the article at b.link/eyzjt8z.

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.