DEAR DR. DONOHUE: I am a 37-year-old man, I weigh 310 pounds and I am 5 feet 7 inches tall. I know this could do me in, but I have tried everything I can think of to lose weight, without any success. I have dieted and have exercised, but weight doesn’t come off. My wife is careful about what we eat. She wants me to have the operation for losing weight. She’s worried about me. I have three young children. What do you think of weight-loss surgery? – B.D.

ANSWER: You have a body mass index of 48.5. The body mass index is a better predictor of future health than is body weight. Your number puts you in the category of morbid obesity, “morbid” meaning “most unhealthy.” Obesity raises the risk for heart attack and stroke. It fosters the development of diabetes and high blood pressure. It promotes cancer of the colon, liver, prostate, kidney, pancreas, breast, cervix and uterus. You aren’t exaggerating when you say that your weight is a significant health problem.

A weight loss of only 10 percent (for you, 31 pounds) of body weight reduces the consequences of obesity. You should lose more than that, however. If you cut back on your daily calories by 500, you should lose a pound a week. In seven months, you’re close to the 31-pound goal. The only way to achieve results is to get a book with the calorie content of all foods. Such books are available in bookstores. Add up your daily calorie intake for one week and then average the result. Deduct 500 calories from that and you’ll have your recommended daily calorie intake. Combine calorie restriction with daily exercise, which can be half an hour or more of brisk walking.

If this regimen fails, then I’d consider surgery. There are several different operations. All of them create a smaller stomach so you cannot eat what you ate in the past. Laparoscopic (surgery done through small incisions and employing a special scope) stomach reduction surgery often can be done, and recovery from this kind of surgery is rapid. It saves lives. Your body mass index qualifies you for this kind of surgery if other methods of weight loss have failed.

DEAR DR. DONOHUE: From time to time you mention body mass index, and I read about all the time in the health magazines I subscribe to. I would like to know how to obtain mine. How do I? – S.P.

ANSWER: Your letter came at an opportune time. It follows on the heels of B.D.’s letter, where the topic came up.

Divide your weight in pounds by your height in inches squared. That means multiply your height in inches by itself. Take that result and multiply by 703 to obtain body mass index, BMI.

Canadians, used to the metric system, can obtain BMI by dividing their weight in kilograms by their height in meters squared.

A normal BMI is 18.5 to 24.9; 25 to 29.9 is overweight; 30 to 39.9 is obese; 40 and above is morbidly obese.

DEAR DR. DONOHUE: You frequently write about ovarian cancer. I wish I had known the symptoms a long time ago. In 1972, my daughter, age 17, was finally diagnosed from it and died at that age despite treatment. She had symptoms that our doctor didn’t recognize. I went to a larger town for an opinion. She had surgery and cobalt treatments. There is no history of cancer in our family. I am writing to show that age doesn’t matter when it comes to this cancer. – M.B.

ANSWER: I don’t have words to express the sorrow I have for parents who have lost a child. The most common kind of ovarian cancer, epithelial ovarian cancer, is a cancer of older women. Bloating, increased abdominal size, fatigue, weight loss, back pain, abdominal pain, pelvic pain and constipation are some of the signs that suggest ovarian cancer. They’re often overlooked.

Germ cell ovarian cancer is the kind of ovarian cancer that occurs in the first two decades of life. Germ cells are the cells that give rise to ova. This cancer grows rapidly. I have a doctor friend whose daughter died of ovarian cancer at the same age as your daughter.

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. Readers may also order health newsletters from www.rbmamall.com.