Great post i just want to add something to this (especially in view of point 2) that is the fact being physically active is under appreciated in general. As a matter of fact the daily caloric intake a person influences to a large extend if not all. The amount of calories a person burns plays a big role in this. For example one could get away with eating some "bad food" and still getting good results. Getting you metabolic rate up is an essential thing the more you burn the bigger chance there is to loose weight, if this is the primary goal.
Without going into detail a practical advice to this is GO FOR A WALK of let say 15MIN A DAY along with all the points mentioned above. Lets make a difference.