sure, going into the movie
The bit about the slusies is at the end of the introduction.
It took me a while to find out how the cannibalism got into the film - it was certainly not in the novel... The producer was trying to sell the film to MGM as an overpopulation film. MGM didn't think that theme was important enough...screenwriter added the cannibalism theme - and they bought it for that...
I do remember, with great pleasure, the opening night of the film. The theatre manager was selling orange and lime slushies to the audience. He enthusiastically labeled the lime "Soylent Greenade." He had of course never seen the film. Going in the audience enthusiastically noshed down the slushies. Exiting later they turned soylent green when they saw the slushy machine.