Obesity has become a global crisis. Although most would agree that eating better and being more physically active are the answer to the problem, researchers have recently become aware that the problem goes beyond just changing individual behaviors. We can convince people of the benefits of healthful eating and regular physical activity, but what happens when they go home to a neighborhood where fresh vegetables are not available and opportunities for physical activity are hard to find? If the environment doesn't help support healthy lifestyles, the change will be next to impossible to...