How is the pathophysiology of obesity?

It is a complex and multifactorial disease where imbalance between energy intake and expenditure (problems in adipose, genetics, pancreas, gut, meds, inactive cessation of smoke, lifestyle) We have interaction among hormonal and neural pathways that regulate food intake and body fat mass (major hormone controlling weight is leptin (stimulates POMC which stimulates paraventricular nucleus releases hypothalamic hormones), Ghrelin on the other hand is inhibitory (stimulates NPY and AgRP to inhibit PVN) So main parts are paraventricular nucleus and arcuate nucleus.