Diet of worms?

I remember wondering what "diet of worms" meant when I was little. I must have seen it in connection with religion because I imagined it was people eating worms as a kind of sacrifice or fast. Anyway, a commenter to Lenin's Tomb has just reminded me of it. Lenin's post quotes the journalist Chris Hedges thus:

Israel’s siege of Gaza, largely unseen by the outside world because of Jerusalem’s refusal to allow humanitarian aid workers, reporters and photographers access to Gaza, rivals the most egregious crimes carried out at the height of apartheid by the South African regime. It comes close to the horrors visited on Sarajevo by the Bosnian Serbs. It has disturbing echoes of the Nazi ghettos of Lodz and Warsaw.

The comment by JamieSW is here:

When Weisglass spoke about putting Palestinians on a "diet", apparently he was referring to animal feed and grass.

Diet of animal feed? Diet of grass? What next, worms? I doubt if the soil could sustain them.