If he's a good kid, don't kick him out.... Just ask him not to bring leftovers home. If he must bring them home, tell him to keep them in his car, or in his room, or someplace where they are not in your sight. Explain to him that you are trying with all your might to lose this weight, and you are trying to control your diabetes without meds, and that weight loss / diabetic diet is not easy, and constant temptation make it all the more difficult for you to succeed. If he loves you and wants you to lose the weight and be healthy, he will understand and do as you ask...
Sometimes, people who have never had to struggle with weight issues, and have never had to diet, they don't realize just how difficult it is to stick to a diet, how hard it is to resist that doughnut
.... willpower is a "you know what"! God, how I miss doughnuts... LOL