Ask the doctors: Readers offer feedback about recent columns

Hello again, dear readers, and welcome to late summer! Please indulge us as we remind you (yes, again) to wear sunscreen, use bug sprays, watch for ticks and stay hydrated. We hope the recent columns about the dangers of excessive heat and the warning signs and physical effects of dehydration were of use to you.

Speaking of summer, here’s an interesting tip from a reader about keeping kids safe in the water. “When swimming and diving, children should be reminded that they have grown taller and weigh more than they did a year ago,” she wrote. These physical changes can mean that the spot where they safely dove or jumped into a pool or pond last summer may no longer be deep enough for them this year, she said.

After reading the column about sushi lovers who wound up with intestinal tapeworms after eating raw salmon, a reader in Gastonia, North Carolina, wondered about the safety of the canned salmon. The good news is that canned salmon is fully cooked and thus is not a risk for tapeworm.

A reader from Fresno, California, who suffers from fibromyalgia wrote to ask whether we know of any clinical trials that she could take part in. The best resource for identifying a clinical trial, which is a rigorously controlled study to evaluate a new medical, surgical or behavioral intervention, is the website clinicaltrials.gov.

We recently cited a study that evaluated changes to muscle mass in obese adults in their 60s who were dieting to lose weight. It’s an important topic because maintaining lean muscle mass is tied to healthy aging. The results of the study were surprising and, it seems, counterintuitive, and we got quite a few letters. We’re happy to repeat (and confirm) the results.

In this study, participants who dieted and did aerobic walking lost more muscle mass than did those who dieted and did no exercise. The group that dieted and lifted weights lost the least muscle mass. Specifically, muscle mass accounted for 20 percent of weight lost in the walking group, 16 percent in the dieting alone group, and 10 percent of weight lost by the weight lifters. Total fat loss was significantly greater among those who combined exercise with diet than in those who only dieted. Dieters who are concerned about maintaining muscle mass may consider adding resistance training to their exercise routine.