Here is a great article about the relationship of wight loss and the spiritual life. Tom Collingwood, mentioned before, has drawn the connections between the health of one’s body, the health of the environment and the Christian life in his book: Becoming a Creation Steward.
This article from CNA explains a Catholic diet developed to lose weight while growing in your faith called: “Light Weight”. It links the emptiness of a faithless life with the compulsion to fill it up with what is unnecessary. By filling oneself up with God, there is no room for eating disorders. Read the article for a full explanation.