 It's on a very long list of things I would never have thought of, but doctors are warning you. When you take selfies, do you suck your gut in? You shouldn't do that because it can affect your breathing. Well, how long are you holding your breath and sucking your gut in for? They say it can have long-term implications, too. It can lead to irregular breathing and a change in the curvature of your spine, all because you wanted a selfie that looked good.