Obese teens' bones strengthened during weight loss

Researchers who boned up on weight loss among obese teens found that their bone mineral content doesn't drop during weight loss.

In a study run at the Children's Hospital of Philadelphia, lead researcher Nicolas Stettler, MD, looked at 62 male adolescents between 9 and 17 who were treated with a weight-loss drug. A dual energy X-ray absorptiometry scanner, they compared the limb and spine bone mineral content compared to 66 healthy adolescents.

They found that unlike adults, who often lose bone mineral content when they lose weight, obese teens' bones keep growing. The lumbar spine measurements increased in the study group, from 0.14 (SD 1.06) to 0.40 (SD 0.94).

However, the bone mineral content in patients' arms and legs increased less than expected. Researchers aren't sure if this is a natural reaction to a change in fat and muscle percentages. Bones that do not grow strong in adolescence are difficult to strengthen during adulthood.