Stem cells from bone marrow make new fat

Some body fat comes from stem cells that migrate out of bone marrow, a new study suggests.

Bone marrow acts as one of the body’s most prolific stem cell factories, pumping out cells that circulate to different parts of the body through the bloodstream. Once these cells reach their destination, they can morph into new cell types—ranging from blood to heart muscle—that fill a specific need or replace cells lost to wear and tear.