Published in the November issue of the American Journal of Clinical Nutrition, the new study found that the bones of people with high body fat were eight to nine percent weaker than those of normal body fat participants. Obesity has already been repeatedly linked to an increased risk of heart disease, stroke, diabetes, cancer, and a host of other health conditions. These growing health risks have already put significant pressure on the food industry for the role it plays in promoting unhealthy eating, pressure which is augmented by these latest findings. "Obesity is an epidemic in this country, and I think this study is critical because it highlights another potential negative health effect that people haven't considered," said study co-author Richard Lewis, professor of foods and nutrition at the University of Georgia College of Family and Consumer Sciences. Lewis and his team conducted advanced three-dimensional bone scans on 115 women aged 18 and 19 with normal (less than 32 percent) and high (greater than 32 percent) body fat. After adjusting for differences in muscle mass surrounding the bones, they found that overweight participants had less healthy bones. Lewis said the exact mechanisms by which excess fat hinders bone strength are unclear, but studies of obese rats show that they produce more fat cells in the bone marrow and fewer bone cells. Since fat and bone cells originate from the same precursor, it may be that fat cell production is favored over bone cell production in obese people. Childhood obesity could be particularly detrimental to bone health. "When you're young you have the capacity to change the shape of your bones, but when you get older you don't have that capacity. And because of that, childhood obesity could have a significant, long lasting negative impact on the skeleton," Lewis said. Obesity is currently thought to affect more than 64 percent of the US's adult population and 16 percent of children. The condition, which has been repeatedly linked to increased risk for heart disease and diabetes, has been the bane of the food industry in recent years, with food firms often receiving much of the blame for the nation's increasing obesity rates.
The list of health problems associated with obesity continues to grow, with a new study linking excess body fat with poor bone health.