A study of 50 premenopausal women indicates there may be a link between belly fat and osteoporosis. According to WebMD.com, many of the women in the group were obese, and those with more fat around the waistline were more likely to have low bone mineral density, a risk factor for osteoporosis.

It's been known for some time that not all fat is created equal. Those with a pear shape who carry their weight around their thighs and buttocks are typically better off than those who carry their weight on their waistline. This is because belly fat - also known as visceral fat - is surrounding many key organs and also tends to be more active, sending out chemicals that have been associated with the development of diabetes. Fat around the thighs and buttocks on the other hand tends to be more benign and even protective.

Previous research has suggested that excess body fat protects against bone loss and osteoporosis. The researchers say that MRI and CT images show that women with excessive visceral fat generally have a more porous bone structure than those without. Also, women with more subcutaneous fat - the fat that lies just below the skin - show more normal bone structure.

MRI spectroscopy showed researchers the different kinds of fat the women had, including fat in the bone marrow. The study showed that the more fat in the bones, the lower the bone mineral density. The same was true for visceral fat, which is also a risk factor for heart disease and diabetes.