"I kept thinking how these guys were basically prisoners, unable to return to their homes or to their normal lives... and how much of the symptoms they exhibited related to this rather than to the inadequate portions of food?"
yup. Serious deprivation: and don't forget they were "offered" this study in lieu of military duty. Enough food = love, or at least a certain sense of well-being, or autonomy, in unpleasant surroundings, in this respect.
(and actually I think the "hoarding" of teapots and such sounds like a sort of elegant twist on wanting to *give* love (or nurture) rather than just keep it for oneself. this also explains the way some of these fellows grew a new interest in feeding others (chefdom)
God bless them --it sounds gruelling, and wholly lacking in human warmth.