Children who are overweight face more than future health problems. They appear to have broken bones and joint problems more often during childhood than kids of normal weight, research suggests.

"A lot of people think that if you're an overweight kid . . . that later on in life you're going to run into having heart disease or Type 2 diabetes," said Susan Yanovski, director of the obesity and eating disorders program at the National Institute of Diabetes and Digestive and Kidney Diseases.

"But kids and adults who are overweight are already having problems with their mobility, fractures and joint pain."

A study led by her husband, obesity researcher Jack Yanovski, found that children and teenagers who are overweight are far more likely to have had a fracture than their ideal-weight peers. They also have more bone and hip joint abnormalities, which can lead to permanent deformities.

The research involved 227 overweight children and adolescents and 128 who were not overweight. The children had an average age of 12. All were enrolled in various federal health studies between 1996 and 2004 and were considered overweight if they were in the 95th percentile of weight and height for their age and sex.

A review of their medical history revealed that 13 percent of overweight kids had had at least one broken bone at some point in their lives, compared with less than 4 percent of ideal-weight children. Similar results were found for how many had muscle, bone or joint pain, and restricted movement.

"The combination of musculoskeletal pain and poor mobility may possibly lead to less physical activity . . . and perpetuate the vicious cycle," said Jack Yanovski, head of the growth and obesity program at the National Institute of Child Health and Human Development. He presented results of the study at a recent meeting of the Obesity Society in Vancouver, B.C.

Children often say their knees hurt, but the real problem is the malformation that is starting to occur in the joint, said Junichi Tamai, a pediatric orthopedic surgeon at Children's Hospital Medical Center in Cincinnati. Being unable to exercise makes the situation worse.

"If a child is very active, chances are the bones are very strong," because weight-bearing exercise promotes bone density, Tamai said.