It has been awhile, but do any of you recall reading the NY Times Magazine article this past August titled "Fat Factors"? It deals with an emerging new science called "Microbesity".
Here is a link, which you will probably have to register to read, but it is well worth it.
Basically, what some scientists have discovered is that some people that are obese may have more of one kind of gut microbe (Firmicutes) than another (Bacteroidetes). This disproportion of microbes may be why some people can eat many calories and gain little weight, and why some obese people eat few calories but can not lose weight. The microbes are designed to determine fat storage, when the scientist played with the ratios in mice they discovered that mice were under or over weight depending on these ratios, though the amount of food was the same.
The implications are fascinating really. Right now as I type this, researchers are testing this theory on humans, taking samples and comparing data. If they find similar results to the experiments and observations on the mice, can a pill containing the proper dose of microbes, or a contrived dose to help obese people lose weight, be far behind?
Don't worry...I am not going to wait for an extra helping of Bacteroidetes...13 days to go!