This is a myth. In fact recent studies show that eating protein will increase bone density, and specifically animal protein. Another study showed that protein increased bone density but only when calcium was also supplemented (however, the same study showed that protein consumed alone did NOT cause calcium loss from bone, it simply had no effect at all). You can read about those studies here: High-Protein Diet Won't Weaken Your Bones.

Many persons who have been following a previous diet that was full of cereal, breads and the like often have low calcium levels. Wheat bran and other grains contain phytates which interfere with calcium absorption from the intestines.

Doreen