There's quite a lot of research with gut bacteria now and the association with obesity. It's not as simple as caloric intake, it is also the balance of the gut

There's quite a lot of research with gut bacteria now and the association with obesity. It's not as simple as caloric intake, it is also the balance of the gut bacteria. http://www.ncbi.nlm.nih.gov/pubmed/17183312 http://www.ncbi.nlm.nih.gov/pubmed/17183312