Goudy, I don't think they're refering to perspiration mixing with bacteria on the skin. That's where the BO smell comes in.
Alot of the toxins in our body are stored in fat, so when we break them down, they get released into our system. That's why people frequently break out like crazy when they diet. It's all the crap leaving that's been stored in the fat, flooding the system. Some toxins are released through the skin, and that could account for the smell. The largest organ of elimination in the body is the skin.