It is commonly thought that the cameras can make you look heavier than you actually are. Dan Vojtech posted this gif on his blog that effectively shows how drastically the focal length of a lens can affect a subject’s shape, and thus its perceived weight.
To frame the face the same in each shot, the camera is close with the wide angle lens and farther away with the telephoto lens, so the GIF above shows what’s known as the “Hitchcock zoom†(or dolly zoom).