Fat helps increase bone size and thickness in girls, according to research.
Fat mass is the amount of fat, measured in grams. Lean mass (total body weight minus fat) is one of the strongest determinants of bone mass throughout life.
A new study shows that fat mass is a strong stimulus for the accrual of cortical bone mass (hard outer layer of bone) in girls, in whom it is more pronounced than boys.
“The effect of fat mass on bone mass appears to be strongest in girls,” said Jonathan Tobias, University of Bristol, who led the study.
“Girls clearly have more fat mass than boys and our findings show that whereas the greater lean mass in boys contributes to their greater cortical bone mass, this effect is partly counteracted by the greater fat mass in girls,” he added.
“Excessive reduction in fat mass could have adverse effects on the developing skeleton, particularly in girls, leading to an increased risk of osteoporosis in later life.”
Researchers used dual x-ray absorptiometry (DXA) to determine total body fat mass and lean mass, and peripheral quantitative computer tomography (PQCT) to measure bone mass in 4,005 boys and girls with a mean age of 15.5 years.
Although lean mass was the major determinant of bone mass, fat mass also exerted an important positive influence, particularly in girls, in which the effect was about 70 percent greater than in boys, says a Bristol release.
The study is slated for publication in The Endocrine Society’s Journal of Clinical Endocrinology & Metabolism (JCEM).
