Brown seaweed may fight the flab.
According to the BBC (September 11th 2006), brown seaweed (used as a flavouring for a number of Asian dishes) contains fucoxanthin, the pigment that provides the brown colour. In tests with 200 mice and rats it was shown to fight the fat in two ways. Firstly, it stimulated a protein, UCPI, which causes fat oxidation; secondly, it causes the liver to produce DHA, a version of Omega 3 that cuts bad cholesterol (LDL).
The seaweed is used to flavour dishes like Miso soup. The pigment is tightly bound and, as yet, no one has produced a natural extract.