Redshepherd brings up a fair point: Sporadic feeding can actually help. I tend to never feed my snakes on a schedule other than to feed growing ball pythons about 80-120% their body weight every 2 months, and adults are kept around certain weights by feeding every couple weeks to as much as every month, depending on the size of the meal and the size of the snake.

My adult female which stops eating is offered food at least monthly until she eats again, then I treat her as a growing snake until she goes off food again, usually puts on 600-1000g before going on a feeding strike again.