My cat is about 15 pounds and he needs to loose weight. Ive changed his food a couple of times (wellness, friskies, science diet-all dry food) but nothing seems to work. Furthermore, he wakes me up every night at 2am sharp because he is hungry. I made one last food change, which is the science diet canned light food. He loves it, bu he still wakes me up at 2 am. He is also very aggressive with me, and only me. He bites and attacks me if I dont give him food. Please help.