If you fill a third of your plate with superfree, which is low in cals, you'll be eating fewer calories overall than if you fill your whole plate with free foods, which are generally higher in calories. It's a way of reducing portion sizes.
Sometimes I paint my nails. It distracts you from eating for a while, and after doing it you can't touch anything for a little while, so you have to stay out of the fridge! Hopefully by then the desire to eat naughty stuff will have passed.