Bringing them into the house triggers a major eating urge. Before we know, we're consuming anything that stays on a plate long enough to get a fork into it. The spiral escalates.
Weight goes up.
No food in the house is safe now. For example, cereal might sit serenely and safely in the cabinet for months. These foods are always safe to have around. Realize everyone has a red light food or two. One is not weak nor doomed to a life of obesity due to a craving for pizza.