Despite advances in understanding the roles of adiposity, food intake, gastrointestinal and adipocyte-related hormones, inflammatory mediators, the gut-brain axis, and the hypothalamic nervous system in the pathophysiology of obesity, the effects of different therapeutic interventions on those pathophysiological mechanisms are controversial. There are still no low cost, safe, effective treatments for obesity and its complications. Currently, bariatric surgical approaches targeting the gastrointestinal tract are more effective than non-surgical approaches in inducing weight reduction and resolving obesity-related comorbidities. However, current guidelines emphasize non-surgical approaches through life-style modification and medications to achieve slow weight loss, which is not usually sustained and may be associated with medication-related side effects. This review analyzes current central, peripheral, or hormonal targets to treat obesity, and addresses challenges and opportunities to develop novel approaches for obesity.