Why did TV’s “Biggest Losers” have trouble keeping the weight off?

DEAR DOCTOR K: I heard about a recent study that explained why the "Biggest Losers" had trouble keeping the weight off. Can you explain?

DEAR READER: You're likely referring to a study done at the National Institutes of Health (NIH). As many readers will recall, NBC television put on a competition reality show for several years, beginning in late 2004. Extremely overweight people competed to see who could lose the most weight, through diet and exercise, over 30 weeks.

Can teens help prevent diabetes through exercise?

DEAR DOCTOR K: My teenage son doesn't like sports or exercise. Diabetes runs in our family. You say exercise protects against diabetes and is valuable even in young adults. Can you give me some ammunition to convince my teenager to exercise?

DEAR READER: Perfect timing: A new study has been published that provides an answer. Most studies of exercise have been in adults, often older adults. Until this recent study, there wasn't a lot of information about teenagers.

Should I be worried about lead in my drinking water?

DEAR DOCTOR K: Like a lot of people, I was shocked by the water disaster in Flint, Michigan. I felt terrible for those people. But then I started to wonder: How safe is my drinking water? Should I be worried?

DEAR READER: The sad answer to your question is that I don't know, and neither may your local department of public health.

What can I take to ease shingles pain?

DEAR DOCTOR K: I've been diagnosed with shingles. What can I take for the pain?

DEAR READER: Shingles, also known as herpes zoster or just zoster, is caused by the varicella-zoster virus. It is the same virus that causes chickenpox. Once you have had chickenpox, the varicella-zoster virus remains in your body's nerve tissues. It is inactive, but it can be reactivated later in life. This causes shingles.

I have dense breasts. Does that increase my risk of breast cancer?

DEAR DOCTOR K: My doctor says I have dense breasts, and a friend says that means I have an increased risk of breast cancer. I'm hoping you'll tell me that's not so.

DEAR READER: I wish I could fully reassure you, but I can't. A woman who has dense breasts does have a slightly increased risk of breast cancer, although not clearly an increased risk of fatal breast cancer.

Can you discuss hormonal therapy to treat prostate cancer?

DEAR DOCTOR K: My doctor has proposed androgen deprivation therapy to treat my prostate cancer. Can you tell me about this treatment?

DEAR READER: Androgens are the family of male sex hormones that includes testosterone. When prostate cancer develops, testosterone contributes to the growth and spread of the tumor. Androgen deprivation therapy deprives cancer cells of this stimulation. Also known as hormonal therapy, it can be a powerful weapon in the fight against prostate cancer.

How can I avoid flare ups of COPD?

DEAR DOCTOR K: I have COPD. What can I do to avoid symptom flare-ups?

DEAR READER: Chronic obstructive pulmonary disease, or COPD, is a long-term condition that makes breathing difficult. Breathing is a lot easier if you take your medicine and do any other therapy as directed.

Could my new diabetes medication be dropping my blood sugar too low?

DEAR DOCTOR K: I'm in my early 80s. I was recently put on a new type of medication for Type 2 diabetes. Since then, I've felt lightheaded a few times and have also fallen twice. Could my blood sugar be dropping too low? What should I do?

DEAR READER: Yes, your blood sugar could be dropping too low. That could make a person feel lightheaded and increase their risk of falling. If you're in your early 80s, you may be at extra risk, because people at that age often have multiple chronic medical conditions.

What are some ways besides testosterone therapy to increase my energy?

DEAR DOCTOR K: I often feel quite tired. My doctor says this fatigue may be caused by my low-normal testosterone level. I'd rather not go on testosterone therapy. What are some other ways to enhance my energy?

DEAR READER: Research studies have not demonstrated a clear value in giving testosterone therapy to men who may be experiencing symptoms of low-normal or slightly low blood levels of testosterone. In fact, some studies have even indicated that such treatments may raise the risk of heart trouble. So I can certainly understand if you'd rather avoid testosterone therapy to relieve your fatigue.