Well portion sizes are smaller, but most people walk, bike or transit to work. For example this week I haven't done any exercise due to a "sports"-related injury, and yet managed to burn an average of 2571 calories -- and before you think I'm lucky to live near work, my one-way commute is 30 miles. Even just 40 minutes of daily physical activity built into a commute can make a huge difference.
Oh yea, totally. I bicycle to work almost every day (it's ~6 mi one way), but I'm lucky enough to live in a location with decent cycling infrastructure. I think another aspect of why most folks drive here (the US) is because a lot of locations have little or no infrastructure for getting around without a car. In the area where I am originally from (different part of US), you'd get smashed by cars pretty fast because you'd be forced to travel on highways/freeways.
