This is interesting. I remember a lecture about obesity back in the day (5 years ago - obsolete), but I also recall the lecturer saying that humans didn't have mutation in the 'ob' gene. I'm not sure if this is the same gene or not, but there may not be any people with problems with this gene, resulting in obesity. Just a word of caution. That being said, artificial manipulation of the hormones would still work in theory. Even if people don't have a broken 'fat' gene, they can still get skinny by correct dosing of the 'skinny' hormone.

In 1999 Japanese scientists discovered the "ghrelin" hormone. And in 2000 American researches discovered that this hormone drives appetite.

Ghrelin is still the only hormone known to directly affect appetite this way. With the developed world getting fatter every year, scientists rushed to learn everything they could about the hormone.

They were able to track the hormone back to a gene, and then they produced a mouse without the ghrelin gene. They expected to have a skinny, emaciated mouse. But the mouse appeared normal.

This remained a mystery until yesterday's announcement by a group of scientists at Stanford. These scientists have discovered another hormone, obestatin, that sends out a signal to eat less or stop eating. It is the anti-ghrelin. But, amazingly, it is coded by the same gene as ghrelin.

So when they knocked out the gene for the hunger hormone ghrelin, they were also knocking out the fullness hormone obestatin. The net effect was an apparently normal mouse.

Oh, I'm doing more lab work and less paper/dissertation writing (some of the former, none of the latter), so I am finding more time on my hands, to be filled by blogging and filling out postdoc apps.