Give up this one sweet treat: chewing gum. Despite the fact that chewing gum goes in the mouth, it does not biodegrade, and you cannot compost it. Old gum that ends up improperly disposed of on sidewalks, lamp posts and everywhere and anywhere else in between is also a health hazard; it can be filled with bacteria and germs from the person who chewed it. And young birds that mistake chewed gum as food can die, since it’s not ingestible. If you do chew gum, wrap it up in a piece of scrap paper and throw it in the trash. But if you want to curtail bad breath, reach for an apple instead of gum: It contains pectin, which helps neutralize odor.