Why do women believe that if they do crunches it will make their waist smaller and get rid of belly fat? And that even if are counting calories and keeping them reasonable, carbs will make them instantly fatter? Where does this information actually come from?

Poor comprehension often coupled with severe confusion regarding both the burden and standard of proof. It's a disease of the mind that afflicts ~ 100% of the population at some point in their lives.

Ignorance, I believe they call it. :P

It is like that game telephone. Where one person says something and by the time it gets to the end of the line, the message is different. And it stays different. Until they come to a place like this or read a health book and learn different.

The belly thing boggles the mind. I really don't know why people think that. And the carbs thing I can see, because of the recent Atkins and such. The carbs are made to look evil, but instead of people actually finding out which carbs are bad for you, they automatically think ALL carbs are bad for you.

Unfortunately there are a lot of health books that aren't totally correct either - they were probably correct for the time that they were written, but not so much now...

There's a ton of misinformation out there... pick up the majorty of fitness magazines... and you'll get inundated with images of ripped looking bodies, promoting the latest magic pill or powder... No need to read the fine print, just take some of this magic elixer and you too will have this body

There's a line from the movie the American President.. that's somewhat relavent to humans..

Replace leadership with the phrase "ability to lose weight and get in shape"

accurate information isn't easy to come by -it gets buried beneath a sea of crap spewed forth by people trying to make some money off the backs of desperate people...