Besides gulping down your food (which of course you try to avoid), gulping air is the most common cause of bloating, says Patricia Raymond, MD
, a gastroenterologist and an assistant professor of clinical internal medicine at Eastern Virginia Medical School. And it's really easy to do without realizing it. If you're drinking your beverage with a straw while reading this, you're doing it right now. You've also been swallowing excess air when chewing gum, sucking on hard candies, chewing on your fingernails or the ends of your hair or talking on the phone while eating. The medical term for air-swallowing is "aerophagia," says Raymond, and the connection is obvious: The air comes in through your mouth, travels down your esophagus and gets trapped in the digestive tract. Fortunately, air that exits from the opposite end of where it enters rarely has an odor, says Raymond, but it still makes you and others around you uncomfortable.