The Eucharist turns consumerism upside down. We do consume in the Eucharist, of course, but we are also being consumed. "St. Augustine hears God say, 'I am the food of the fully grown; grow and you will feed on me. And you will not change me into you like the food your flesh eats, but you will be changed into me.'" We are "absorbed into a larger body."
We also become food for others. Cavanaugh cites Matthew 25, where Jesus says that whenever we serve another, we serve him.
What is truly radical about this passage is not that God rewards those who help the poor; what is truly radical is that Jesus identifies himself with the poor. The pain of the hungry person is the pain of Christ, and it is thus also that the pain of anyone who is a member of the body of Christ. If we are identified with Christ, who identifies himself with the suffering of all, then what is called for is more than just charity. The very distinction between what is mine and what is yours breaks down in the body of Christ. We are not to consider ourselves as absolute owners of our stuff, who then occasionally graciously bestow charity on the less fortunate. In the body of Christ, your pain is my pain, and my stuff is available to be communicated to you in your need, as Aquinas says. In the consumption of the Eucharist, we cease to be merely "the other" to each other. In the Eucharist, Christ is gift, giver, and recipient; we are simultaneously fed and become food for others.