For quite some time, many researchers and lay people alike have subscribed to what is known as the "Thrifty Genotype Theory." Basically, this theory suggests that cycles of feast and famine that occurred early in human history created a gene that assists the body in utilizing scarce nutrients.

Because we as humans no longer operate on a feast or famine eating cycle, however, this gene (which still remains) leads to obesity, so said the theory. In addition, this theory pointed to certain ethnic groups; Native Americans, Mexican Americans, African Americans, Australian Aborigine and other indigenous groups as being genetically prone to obesity and type 2 diabetes because of their link to this particular gene.

In efforts to challenge the ethnic presumptions, and erode the "Thrifty Genotype Theory" altogether, a 2007 study by U.S. and Australian researchers examined existing genetic studies published across a variety of disciplines. Whereas past studies into the genetic link to diabetes failed to control for outside variables, this new study factors in poverty, housing segregation and poor diet -- and, upon completion of the researchers' analysis, all were found to be stronger indicators of obesity and diabetes than genes.