By Deborah Kotz, Globe Staff

Here are some of the best comments that I received from readers this week.

By Carolyn Y. Johnson and Deborah Kotz, Globe Staff

Raising levels of “good” cholesterol may not be so good for you after all. A study published Wednesday by Boston-area scientists challenges the long-held idea that HDL cholesterol actively protects against heart disease, finding that people with genes that boosted their HDL did not have a lowered risk of heart attacks. In the study appearing in the medical journal The Lancet, researchers examined the health of more than 100,000 people, some of them with genetic variations that elevated their levels of HDL, and found that these genetic variations did not protect against heart attacks.

By Deborah Kotz, Globe Staff

In order to reverse the American obesity epidemic that has left 1 out of 3 children and 2 out of 3 adults overweight, the nation needs to pool its resources to implement a number of key steps, according to 462-page report issued Tuesday by the influential Institute of Medicine.

While the report has earnest goals, the suggested measures -- exercise more, eat healthier, get schools involved in obesity prevention -- have been underscored and proclaimed by others time and time again.

By Deborah Kotz, Globe Staff

Lyme disease cases could reach record numbers this year due to unseasonably warm temperatures this winter and spring, which is causing the deer ticks that carry the disease to breed sooner. What to do to protect yourself and how to recognize the symptoms.

By Deborah Kotz, Globe Staff

It’s tough to tease out just how much of a role genes play in determining our body weight, but University of Washington researchers gave it their best shot, comparing the body mass index and sleep habits of twins. They found that genes play far less of a role in determining BMI when people get more than seven hours of sleep per night.