I read a 1972 article on Left sugar (commonly referred to as L-sugar) which is an enantiomer (mirror image of a molecule) of regular sugar. The human digestive tract is light-sensitive, rendering the digestive tract enzymes unresponsive to the distinct refraction waves created by the molecules of L-sugar. This means that it is not digested and therefore can be used as a weapon against the growing mass of fat in the U.S. So why has it not been used in the making of everyday food products?
Mabey because some of the 70s products contained extra added drugs?
It hasn’t been possible to produce left-handed sugards in a cost-effective way. I believe that there was a recent breakthrough that removed that obstacle, but I don’t have a cite handy.
It’s called D-tagatose. It also looks like it’s just finishing up being studied–long-term experiements on rats and pigs and things, to make sure it doesn’t cause cancer or something.
http://class.fst.ohio-state.edu/fst621/Lectures/Sweet/Taga.htm
It’s #78.
http://www.cfsan.fda.gov/~rdb/opa-gras.html
http://www.cfsan.fda.gov/~rdb/opa-g078.html
They just started evaluation procedures for it in Oz and NZ, too.
http://www.anzfa.gov.au/_srcfiles/A472_IAR_091002.pdf
Duck Duck Goose: You must love that Google? (Google:named by its originial owner Mathemetician…its one million millions)
But L-sugar was supposed t be entirely indigestible (as I understood.) There wouldn’t be any partial absorption–it would go straight through the digestive tract and be, um, excreted.
Well, unless there are two “enantiomer sugars” out there. D-tagatose was what came up on Google for it.
Maybe since 1972 they found out that it is partially digestible after all. That would explain why it wasn’t rushed into production as a diet aid, if it isn’t really “calorie-free”.
See, that’s what you get for reading science articles from the Nixon Administration. Now tell me how we’re all going to have computer-controlled flying cars in the year 2000. 
We will.
(Nope. It was googol–which is a lot more than a million million.)