the same way as eating nothing all day, except a banana for breakfast and a carrot for lunch and a "healthy meal" for dinner will.
its just a way to get you to eat more of their cereal.
Diet is easy, eat healthily, and small portions. Lots of fruit and veg. Most importnatnly walk if you can't run for as long as you can every day. Walk 1 hour to work every day and you will see the weight fall off.
Hey yes this does work, i did it with just one bowl for lunch and just a small dinner. The weight fell off me, though like squashball says - it works the same as just having 1 bread roll and one small dinner, or one piece of fruit for breakfast and lunch and a small dinner!