Up until now experts considered one of the few benefits of being overweight was that your risk of developing brittle bones - or osteoporosis - was lower than normal. That's right, excess fat was believed to protect against bone loss.
According to the National Osteoporosis Society, one in two women over the age of 50 will break a bone mainly because of poor bone health, with almost three million people living in this country thought to have osteoporosis.
But why would excess tummy fat increase your risk? According to the US researchers, who scanned the vertebra of 50 overweight women, those with more visceral fat - that's fat found deep under the muscle tissue in the abdominal cavity - have increased bone marrow fat and decreased bone mineral density.
"Our results showed that having a lot of belly fat is more detrimental to bone health than having more superficial fat or fat around the hips," says lead researcher Dr Miriam Bredella.
Osteoporosis tends to strike women and men in later life - but does that mean you don't have to worry about it until your older?