It's an unconfirmed bit of information from a Representative in the Lower House of Japan's Diet.
Yukiko Miyake says she had a chance to talk to Banri Kaieda, ex-Minister of Economy, Trade and Industry who lost the bid to become the party leader and the prime minister. According to her tweet on September 16:
I had a chance to talk to Mr. Kaieda during the main session of the Diet. I had told him two days ago about the free lunches for the [Fukushima I] workers that were stopped. He immediately did some research, and said to me the following: "It is true that the free lunches were stopped, because the emergency boil-in-the-bag food ran out. But we have to worry about internal radiation exposure for the workers, and I think the boil-in-the-bag lunches are safer. I think boil-in-the-bag food is in stock throughout Japan."
So, TEPCO may have run out of boil-in-the-bag food stocked at Fukushima I and at J-Village, and it couldn't buy more and/or it couldn't ask for more.
I wonder how Mr. Kaieda is doing these days, relieved of the ministerial job. My personal vote for the new PM was actually Kaieda, despite all the badmouthing I did of him. Unlike ex-prime minister Kan and ex-cabinet secretary and current Minister of Economy and Trade Edano, Kaieda hasn't appeared in the media circuit (I almost wrote "circus") to peddle "his side" of the recent 6 months history of Japan's nuclear crisis.
New Prime Minister Noda has gone very quiet after becoming the PM, with some questionable appointments of ministers and party leaders including Mr. Maehara, who was revealed in WikiLeaks to have been informing Americans about Japanese politicians like Ichiro Ozawa.