Insulin resistance is a prominent pathophysiologic syndrome in a plethora of metabolic disorders including obesity, prediabetes, type 2 Diabetes Mellitus (Ten et al., 2007), impaired glucose tolerance, dyslipidemia, polycystic ovary syndrome and hypercoagulability (Smith & LeRoith, 2004). It is strongly associated with obstructive sleep apnea, hypoventilation syndrome, pancreatitis, nonalcoholic fatty liver disease, steatohepatitis, cirrhosis, gall bladder disease, multiple cancers (breasts, uterus, cervix prostate, kidney, colon, esophagus, pancreas and liver), stroke, cataracts, coronary heart disease, and hypertension. It is also associated with causation of abnormal menses, infertility, polycystic ovary syndrome, osteoarthritis, phlebitis and other venous diseases. Insulin resistance is thought to be caused by intrinsic and extrinsic factors that contribute to its development. Once present, insulin resistance affects the metabolism, behavior, physical appearance and has lasting effects. This paper will review the latest evidence in development of insulin resistance, its pathogenesis and manifestation and its relation to other conditions. The final aim is to raise awareness of its role on diet, metabolic, genetics and microbiome.