By monitoring the overall health of the snake, weight loss, by making sure the animal remains well hydrated etcHow do you know if this behavior is detrimental to the snake's health
By addressing the underlying cause such as husbandry/stress issue which is often the number 1# cause among new owners.How do you rectify this issue ?
Also keep in mind that even with a optimal setup sooner or later BP do go off feed especially when reaching sexual maturity.
Large individuals going off feed for extended period of time is not abnormal nor anything to be concerned about in most cases just something that can be very frustrating for a new owner, a way to eliminate that frustration is to understand how efficient those animals how when it comes to their metabolism.