One explanation for that weight loss may be that he perceives that the food served by the Connecticut Department of Corrections is not certifed as kosher. He filed a lawsuit stating that he has been suffering emotional injury because he is caught between the laws of his religion as an Orthodox Jew and eating to survive.
As AP reports in the New Haven Register, U.S. District Judge Alvin Thomas denied Hayes' motions for a hearing and injunction. However, the judge didn't toss the lawsuit. Here is the coverage.
Another explanation for the dramatic weight loss may be that Hayes is on a stealth hunger strike. He just may have decided to take his death into this own heads and out of the jurisdiction of the state.
Meanwhile, the one survivor of that home invasion which ended in three murders Dr. William Petit still has flashbacks. He has a new wife and son but fears he won't be able to protect them, just as he was unable to protect his wife and two daughters from Hayes and the other killer Joshua Kosmisarjevsky. Both the guilt and setencing trials of both men were covered by national media. The crime was positioned as senseless as that chronicled by Truman Capote in "Cold Blood."
Connecticut has banned the death penalty. However, that was not made retroactive for Hayes and Komisarjevsky.