Being "big boned" as a kid is one thing. But having big bones doesn't mean the bones are strong and dense.
As levels of children's abdominal fat goes up, their bone mineral density goes down, new research shows.
The findings show that abdominal obesity could be a factor in osteoporosis development in children, according to researchers.
Researchers, led by Ismael Junior, from the Department of Physical Education at UNESP, Universidade Estadual Paulista in Brazil, looked into whether abdominal obesity in children negatively impacted their bone density.
The study included 175 obese children and teens ranging from 6 to 16 years of age. The kids were not regularly active within the last three months before the start of the study and did not have cardiovascular disease.
More than half the kids were girls. Through a series of drawings representing five different stages of puberty in girls and boys, participants chose the drawing that most resembled where they were in their development.
Researchers measured the participants' bone mineral content and density using dual-energy X-ray absorptiometry, a device that provides detailed photographs of tissue and bone structure.
Researchers also took ultrasounds of the kids' abdomens to measure the thickness of their adipose, or fat, tissue.
As fat tissue increased in the abdomen, bone mineral density declined in both boys and girls, researchers found.
Age, stage of puberty, height and weight were linked with bone mineral density by itself. However, the link between bone density and abdominal fat was independent of the child's age and puberty status.
"In summary, our findings indicate that abdominal obesity negatively affects the bone density of obese children and adolescents, indicating that abdominal obesity could be a determinate in the development of osteoporosis in adulthood," researchers wrote in their report.
"Further studies should analyze whether this negative effect also occurs in non-obese youth."
Researchers noted they are not sure why increasing abdominal fat was linked with a decline in children's bone density. They also did not measure factors that are also linked to bone density, including children's calcium and vitamin D intake.
The study was published online March 20 in the journal BMC Pediatrics. No conflicts of interest were declared.