For Jesus is the Word as well as flesh. We are to consume Him wholly, taking His teachings and His very self into us, making Him a part of us. Just as the food we eat binds within our bodies at a molecular level, so should our relationship with Jesus.
This is a difficult diet that, like most diets, requires sacrifice and willpower on our part. It is easy to fall off such a diet. However, only by going back to it will our lives be sustained.