We saw this French oldie two days ago and I loved it.
This film is dark, funny, sad, grotesque, caricatural, over the top, and very, very different from today’s blockbusters. A real treat!
(Thank you M. For the recommendation.)

From the wikipedia page:
The film tells the story of four friends who gather in a villa for the weekend with the express purpose of eating themselves to death. Bouffer is French slang for “excessive eating”. (the Italian abbuffata means “great eating”).

Links:
Rotten Tomatoes’ audience gives it an 84%.
La Grande Bouffe at Wikipedia

Trailer (in German because I couldn’t find one in English or the original French):