Obesity is not synonymous with insulin resistance. Why some but not all individuals develop insulin resistance with weight excess is not clear, but a number of plausible hypotheses with ample support now exist. This article reviews regional fat distribution, inflammation, lipotoxicity/ectopic fat and impaired adipogenesis as leading theories as to why excess body weight has the potential to promote insulin resistance.
Keywords: adipose cell; adipose tissue; impaired adipogenesis; inflammation; lipotoxicity; regional fat distribution.