What I found most enlightening is that our ability to smell another's body odor is how we know what mate would be good... as far as health, genes etc.
Anyone who has ever had a loved one who died slowly knows the "smell of death"... and that is apparently only one of many pieces of information our odor communicates..
Here is an excerpt
For the most part of what i've read of these comments, it seems that no-one has yet addressed that a persons state of health and diet is the major contributer to body odours. You can be a person that bathes, shampoos and deodorises regularly but still stink offensively to high heaven from poor food choices, lack of fruit and veg, too much processed junk and the degenerative diseases developed. On the other hand, you can be a person who is physically active on a daily basis, eats only fresh food, lightly cooked meats and seafoods, avoids grain foods (because we are NOT birds) and smell perfectly fine from not using cosmetics and soaps, etc. To determine/decide if another potential mates' odour was offensive or not is one of many important evolutionary 'tools' to ensure that humans mated with other humans who were in good health with good genes. Cosmetics were originally developed to mask a persons poor health, rather than making the effort to improve their health (more like ignorance in the face of decadence).
(visit the link for the full news article)