Obesity is a chronic, systemic and multifactorial disease, actually considered a major public health problem due to its exponential and epidemic growth during the last decades worldwide. The high impact of this disease has increased the interest of the scientific community to fully understand its various etiological routes, in order to use these theoretical bases for the development of effective preventive and therapeutic methods. Obesity is the result of an interaction between genetic, behavioral and environmental factors that may affect the response to diet and physical activity. The recognition of the complexity and multifactorial nature require the dedication of impetuous efforts involving multidisciplinary intervention. It is why this article seeks to encompass the most important aspects of genetic and psychosocial interactions related to the development and consequences of obesity, specifically the association between individual factors such as personality traits and early maladaptive schemas, the link between this pathology with life events and genetic variability finally involved in susceptibility to their appearance.