Is there a specific term for someone who works for food and does not get paid?

Question

Someone works in a job where he does not get paid for it but rather just gets meals. Is there a specific term/title for that particular type of work?

Answer 1

If working for room and board is exchanging labor for a place to live and food to eat, then you could say that working for board is exchanging labor for food.

According to Ngrams, the phrase is not as uncommon as I supposed it might be.

Answer 2

Subsistence may be the answer. As in M-W, it means the minimum (as of food and shelter) necessary to support life.

The definition of European Customs Portal for Subsistence worker can also shed more light.

Subsistence workers are workers who hold a "self-employment" job and in this capacity produce goods or services which are predominantly consumed by their own household and constitute an important basis for its livelihood.

Also, Not a surprising answer but as introduced in the OP, Work for ... is a suitable title.

To work in exchange for something, as a sum or salary of money. e.g. I offered to work for food and supplies, since they didn't have any money to pay me.

To provide labor in exchange for something. e.g. The traveler didn't want any money; he said he would work for food.