Surprisingly, researchers have known for more than a decade that most weight-related medical problems can disappear, with no focus whatsoever on weight loss, if individuals simply increase their pleasurable physical activity. Happy children are more interested in movement-related play than adults are. In most cases, children merely need the right opportunity and companionship to get up and move around. Their young bodies respond more quickly than mature bodies, and the positive experiences are self-reinforcing, leading children to seek to repeat these experiences. By getting up and moving around, they will not only stop summer weight gain, but also lose in a healthy manner any weight they may have gained.