America is in the midst of an obesity epidemic, which is slated to only get worse over the next decade. An extra 20 minutes of physical activity a day, or an additional 2,000 steps, is all we need to avoid weight gain, according to Dr. James Hill, obesity researcher and co-founder of America on the Move. How do you know how many steps you're taking? Clip a pedometer to your belt and get moving! Everything from walking the dog to grocery shopping counts.