I have been teaching seniors a chair exercise called "Zookinesis" and found it to be very effective for weight reduction. It is more vigorous than it sounds. Some people just can't stand up for long periods of time.
I also have a theory about diet. I think that while your stomach may be full, if you don't eat nutritious food your cells still won't be getting the chemicals they need. The individual cells can still be hungry, so even though you just ate a lot of food you will still be hungry.
In my exercise classes I suggest that people eat whole foods and organic foods - even substituting Turbinado sugar for refined sugar. This way the cells will get and stay full.