Why does my dog do this?

Hi, my dog is 5 years old and he is fed as normal a full tin at 6PM every day, but he is so obsessed with food. You might be thinking every dog is like that but whenever any of my family has food he will stare at them and then told to go away but he will just sneak back and watch again. Even if I have a bowl of cereal or a little biscuit he watches me from the stairs and yesterday I had to shout at him to go away 4 times but then he just looks at me through the corner of his eye at the banister. My entire family are sick of it! 1 night I even fed him 2 full tins to see if he was getting fed enough and he never managed to eat it all. Need help sick of him staring at us any chance he gets and also he goes through my bin, kitchen bin and my other family member’s bins for food. Earlier I dropped I tiny bit of food so he comes rushing downstairs. When I take him out for a walk sometimes he nearly got killed once because he was pulling me on the road to get a it of food and when I pull him back he chokes himself till he gets to it! Please help me and right now he’s staring at me through the tiny opening of my door because im eating maltesers.