He who eats my flesh and drinks my blood lives in me and I live in him. As I, who am sent by the living Father, myself draw life from the Father, so whoever eats me will draw life from me.
Cf. John 6: 51-58
"Ordinary food is digested and changed into us...absorbed into fat, muscle, bone, hair etc.. With the Eucharist, it is we who are changed into what we receive. We become more Christlike in our thinking, values, attitudes, moral strength and apostolic zeal. We draw life and spiritual energy from Christ just as the hungry body is restored by food. "
(From Fr. Silvester O'Flynn ofm cap. in Sunday Seeds. 20th Sunday in Ordinary Time (B)
I like the above image, We are strengthened every day by eating nourinshing food, this helps us to grow and to stay healthy. We know this also because medical and dietary experts encourage us to eat well. This fuels our physical and spiritual health - our holistic wellbeing. Eating junk foods regularly will have the opposite effect and this is well known. We become what we eat as it were in one way or the other.
Jesus encourages us to receive him, to eat his flesh and drink his blood as a way of being spiritually healthy. This action, lived in the now, has a direct effect on how we take care of ourselves, each other, and the world around us. It also fuels us for our life with Him beginning today and for the eternal life to come after we die. When we receive the body and blood of Christ at Mass, we are being strengthened on the inside for our day to day lives. I see this especially when I bring Holy Communion to the sick in their homes in the parish, especially on the First Friday. It becomes a focal point for them and a source of strength for them. They may be weak or have limited mobility on the outside, but they are strong within. They become what we receive.