A great way to start is switching one meal to a snack, whichever meal works best for you. Instead of a full plate, have a protein shake, or a couple pieces of jerky and a small hunk of cheese, big swig of kefir, or a banana with a cup of oats and butter, a few chicken wings with sauce. Pick one meal at least twice a week to downsize. Hunger is partly a mental game because your digestive organs have a small neural network around it, to allow the billions of digestive bacteria to communicate with your brain. Whatever your digestive bacteria want in order to survive will be communicated to your brain. The key to changing diet is to do it slowly, but steadily. It's like climbing back down a mountain, every step deliberate and according to a plan.