The more energy you have, the less stuff you need.
The less energy you have, the more you need things to make you happy; the more food you eat to fill up your belly and yet the heavier you feel. A fuller belly in this case doesn't equal a fuller life.
If you learn to gather energy through Qigong practice and make your body light, your body can make good use of the food you eat and you can enjoy the things you have without wanting more and more. In this case, it's not just food for your stomach but food for your life!