I agree with the suggestion to visit your vet. Many years ago, I had a wonderful cat who seemed to become ravenous - he'd eat everything as soon as he could get it in his mouth. He also tended to lay around more. I took him to the vet and asked if he was diabetic. The vet asked me why in the world I thought my cat was diabetic (after all, I'm not a medical person) and I told him I thought my cat was diabetic because he was acting just like my husband, and my husband was diabetic. The vet laughed at me, but guess what? My cat was diabetic. I learned to give him insulin every day.