A few ‘obesogenic’ animal viruses discovered so far: http://www.virology.ws/2009/01/30/viruses-and-obesity/ Also, modern gut flora could lead to different absorption rates.
A few ‘obesogenic’ animal viruses discovered so far: http://www.virology.ws/2009/01/30/viruses-and-obesity/ Also, modern gut flora could lead to different absorption rates.