The indwelling Spirit of God will sustain you like real food. God’s spirit is not just an idea that you subjectively ponder, he is a real presence in the deepest part of your being. And His presence nourishes your soul, mind, and bodies better than physical food. Like Jesus, we have the food of the spirit of God that will sustain us and make us whole.

John 6:53 Jesus said to them, “Very truly I tell you, unless you eat the flesh of the Son of Man and drink his blood, you have no life in you. 54 Whoever eats my flesh and drinks my blood has eternal life, and I will raise them up at the last day. 55 For my flesh is real food and my blood is real drink. 56 Whoever eats my flesh and drinks my blood remains in me, and I in them. 57 Just as the living Father sent me and I live because of the Father, so the one who feeds on me will live because of me.

"Jesus becomes as truly assimilated to the life of the individual as the nourishing elements in food enter into the substance of the body. The believer abides in Christ as finding his life in Him (Galatians 2:20); and Christ abides in the believer, continually imparting to him what constitutes spiritual life. For in Christ man reaches the source of all life in the Father (John 6:57), The living Father has sent Christ forth as the bearer of life. The Father is the cause of my life; I live because the Father lives. The Father is the absolute source of life; the Son is the bearer of that life to the world. Everyone that eateth Christ will by that connection participate in the life of God." excerpt from Expositor’s Greek Testament on John 6:55-56