I know this is going to sound crazy, but it seriously helps me not overeat. It doesn't take a whole lot of change to incorporate this into your lifestyle, so it's something you can start today.
Before I eat anything or drink a cup of coffee, I will drink a small cup of water. During my meal, I will drink another cup of water. I eat a whole lot less and don't feel hungry at all.
One of the symptoms of dehydration is a feeling of hunger. Many times we mistake true hunger by not staying hydrated properly. If you find yourself staying hungry often, check your water intake.