Livro onde alienígenas estão selecionando humanos para consumo alimentar

Pode muito bem ser o conto 1950 de Damon Knight "Servir ao Homem". Ele se encaixa no prazo de Lewis e Clarke (trocadilhos).

A sinopse, da Wikipedia (abreviada):

The story opens at a special session of the UN where three alien emissaries are testifying that the purpose of their mission to Earth is to bring humans "the peace and plenty which we ourselves enjoy, and which we have in the past brought to other races throughout the galaxy". The aliens soon supply Earth with cheap unlimited power, boundless supplies of food, etc. As a further token of friendship, they allow humans to visit their home planet via ten-year "exchange groups".

The narrator has trusted the emissaries from the time of their arrival, but his friend Grigori is certain that the aliens have an ulterior motive. He takes a job at the alien embassy to learn their language. This affords him access to an alien dictionary, and he later steals an alien book, hoping to translate it.

The two determine that the book's title is How to Serve Man. Two weeks later, the narrator returns from a trip to find Grigori distraught, having discovered to his horror that the title is a double entendre. Grigori has translated the first paragraph of the book and has determined that it is not a treatise on serving humanity, but a cookbook.