i worry about your dog! unfortunately i have no way of determining a reason over the internet. i do not know yoru complete medical history nor do i have the ability to examine you or run any diagnostic tests. see your medical provider. hopefully you will be able to get to the bottom of this ravenous behavior.
i am extremely hungry when i wake up form naps & find myself eating any and everything that first comes into my sight. i am rather active run daily and eat rather well. i thought the problem may have been sleep deprivation but i've been going to sleep early & getting plenty of sleep and it still happens.