Does juicing live up to the hype?

DEAR DOCTOR K: Are the benefits of juicing as great as I've heard?

DEAR READER: Juicing -- extracting the juice from fresh fruits and vegetables -- appears to be the latest trend for anyone looking to detoxify, lose weight or just get healthy. But does research support the claims that juicing can reverse chronic disease, jump-start weight loss and "detox" the body?

Could insomnia be responsible for my recent weight gain?

DEAR DOCTOR K: I've been suffering from insomnia for the past year or so. I've also gained 15 pounds over the same time period. Could the two be connected?

DEAR READER: I spoke about this with my colleague Dr. Stuart Quan, professor of sleep medicine at Harvard-affiliated Brigham and Women's Hospital. He confirmed that there is growing evidence of a link between obesity and insufficient sleep. The growth of this country's obesity epidemic over the past 40 years, for example, correlates with a decline in the amount of sleep reported by the average adult. And in large population-based studies, obesity has been linked to less sleep.

Could my son get the mumps even if he’s had the MMR vaccine?

DEAR DOCTOR K: A few students at my son's college have been diagnosed with mumps. My son has had all of his vaccines, including the MMR. Could he still get mumps?

DEAR READER: Mumps is an infection that causes swelling of the parotid glands in front of each ear. It is caused by a virus that spreads from person to person through coughs, sneezes and saliva. It can also spread through contact with contaminated items and surfaces. Once the mumps virus enters the body, it passes into the bloodstream and can spread to many different glands, as well as the brain.

Have there been any recent advances in cataract surgery?

DEAR DOCTOR K: My husband had cataract surgery 10 years ago. Now it's my turn. Have there been any advances in the past decade that I should know about?

DEAR READER: A cataract is a clouding of the lens of the eye. It commonly causes poor vision and blindness among older adults. But cataracts can be surgically removed and replaced with artificial lenses. In fact, cataract surgery has become fairly routine. The vast majority of people who undergo this procedure have excellent outcomes.

Why am I losing muscle as I age?

DEAR DOCTOR K: I'm in my 60s. Despite exercising regularly, I have been losing muscle as I get older. Why does this happen, and is there anything I can do about it?

DEAR READER: As the years pass, muscle mass generally shrinks and strength declines. It happens to all of us as we age --- even Arnold Schwarzenegger. The key to slowing this process is strength and power training.

Can you recommend nonsurgical treatments to help my face look younger?

DEAR DOCTOR K: I'm 65, and my face is starting to look old. Can you recommend nonsurgical treatments to take a few years off my face?

DEAR READER: Our faces age along with the rest of us. The difference is that our face is the part of ourselves that we look at most often -- and that others look at most often. Some people accept these changes; others fight them every step of the way. But there's also a middle road for people who prefer to make relatively small tweaks that can make a noticeable difference.

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.