DR. WALLACE: I'm 16 and very slender. I usually eat healthy food, but I'm not what you'd call a "health nut." I try not to eat too many junk foods, and I'm on our cross-country team in our high school.

My problem is that I have a grandmother who lives with us from Poland, and she doesn't speak very much English yet, but she is a really nice person. She speaks in Polish to my mom (who also speaks Polish), and she is trying to convince my mom that I'm too thin and if I don't start eating more I'll get really sick. I know this isn't true, because I'm physically fit and healthy, and I haven't missed a day of school in five years! However, my mom is starting to wonder if I could be anorexic.

Trust me when I tell you that I am not anorexic. I enjoy three meals a day and I eat snacks like raw vegetables and fruits. My grandmother makes a lot of Polish recipes and they look delicious but I try to avoid most of what she makes because her cooking is loaded with calories. My grandmother thinks I don't eat enough, but she is quite plump, and it is partly because of her diet.

How can I convince my mom and grandmother that I'm not undernourished and that I'm physically fit and don't need the extra calories? I don't want them to keep worrying about my health. Help! — Vicky, Northwest Ind.

VICKY: There are generally three different body types: slim, medium and bulky. You are simply in the slim category. This means that it's more difficult for you to add 10 pounds than it is for someone with a bulky build.

By eating a proper diet and exercising regularly, people of any body type can enjoy excellent health. The fact that you are eating three meals daily and snack on raw veggies and fruits is evidence that you are not anorexic. Health experts agree that if a person is eating properly, it is almost impossible to be too thin. Make sure your mom reads my answer and shares it with Grandmother.

As a teenager, I grew up in your area with many Polish-American families in Northwest Indiana. I can vouch for Polish cooking and baking. It doesn't just look delicious — it is delicious! It takes extreme self-discipline not to overeat that wonderful food.

MARIJUANA WILL NOT CAUSE FATAL OVERDOSE

DR. WALLACE: Can a person who uses marijuana on a regular basis actually die from an overdose of pot? Which is more dangerous for a person's health: being addicted to tobacco products or smoking a couple of joints every day? — Nameless, Lima, Ohio.

NAMELESS: Drug experts agree that marijuana will not cause a fatal overdose. But regular marijuana smoking can cause physical ailments that can lead to premature death. Research has shown that one marijuana cigarette can cause as much lung inflammation as seven to 20 tobacco cigarettes.

Pot smokers generally consume less than tobacco smokers do, but they hold the smoke longer in their lungs. Because marijuana smoke has more cancer-causing chemicals than tobacco smoke, those who smoked 10 marijuana cigarettes a week for five years were found to have similar swelling, redness and changes in lung cells as cigarette smokers who had consumed two packs a day for 20 years, according to the publication "Marijuana and Health," printed by Life Skills Education in Weymouth, Mass.

The wise teen who strives to have a healthy body avoids both tobacco products and marijuana.

Dr. Robert Wallace welcomes questions from readers. Although he is unable to reply to all of them individually, he will answer as many as possible in this column. Email him at [email protected]. To find out more about Dr. Robert Wallace and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.