Losing weight after delivery isn't all that different from losing weight at any other time, experts say. It mostly requires getting off the couch. Harvard doctors found that regular walking significantly lowered the risk of retaining pregnancy weight one year after childbirth. But the more television a woman watched and the more food she ate that was high in trans fats, the less likely she was to lose weight. Women who hold onto the extra weight are at risk for obesity and cardiovascular disease later in life.