A method is described for the treatment of obesity or other disorders, by electrical activation or inhibition of the sympathetic nervous system. This activation or inhibition can be accomplished by electrically stimulating the greater splanchnic nerve or other portion of the sympathetic nervous system using an implantable pulse generator. This nerve activation can result in reduced food intake and increased energy expenditure. Reduced food intake may occur through a variety of mechanisms that reduce appetite and cause satiety. Increased adrenal gland hormone levels will result in increased energy expenditure. Fat and carbohydrate metabolism, which are also increased by sympathetic nerve activation, will accompany the increased energy expenditure.