The well-being of the global population has been challenged with the epidemic of obesity. Obesity is a complex and multifactorial health hazard. While obesity itself can be considered as a metabolic disease that reduces quality of life and life expectancy, the occurrence of a variety of obesity-related complications including cardiovascular diseases, cancer, type 2 diabetes, renal dysfunction, liver defect, mobility limitations and neurological/psychological disorders also contribute to the human and economic burden of obesity. Therefore, advancement of the understanding of the mechanisms as well as causes of obesity can further our knowledge such that appropriate and concerted efforts for prevention of obesity and associated health problems can be undertaken. Since successful therapeutic strategies for obesity are not a one size treatment fits all approach, they involve multifaceted and long-term efforts that can be designed to the individual. Accordingly, this chapter is intended to introduce some of the major causes of obesity as well as the nature and prevalence of obesity-related co-morbidities. In view of the influence of sex and ethnicity in the incidence of obesity and related disorders, some discussion is also provided to identify specific populations at risk for obesity as well as to obesityinduced health complications. Furthermore, some of the therapeutic approaches to prevent or treat obesity that can be tailored to the individual are outlined. From the information provided it is evident that obesity is a major health hazard and appropriate public health measures should be implemented to prevent or reduce or even reverse the impact of this global chronic disease.