Soylent Green

Soylent Green is a 1973 dystopian science fiction movie depicting a bleak future in which overpopulation, global warming, and the resulting severe damage to the environment have led to widespread unemployment and poverty. Real fruit, vegetables, and meat are rare, expensive commodities, and much of the population survives on processed food rations, including "soylent green" wafers.
The film overlays the genres of science fiction and the police procedural as it depicts the efforts of New York City police detective Robert Thorn (Charlton Heston) and elderly police researcher Sol Roth (Edward G. Robinson) to investigate the brutal murder of a wealthy businessman named William R. Simonson (Joseph Cotten). Thorn and Roth uncover clues which suggest that it is more than simply a bungled burglary.
The film, which is loosely based upon the 1966 science fiction novel Make Room! Make Room!, by Harry Harrison, won the Saturn Award for Best Science Fiction Film in 1973.
Food as we know it today–including fruit, vegetables, and meat–is a rare and expensive commodity. Half of the world's population survives on processed rations produced by the massive Soylent Corporation (from soy(bean) + lent(il)), including Soylent Red and Soylent Yellow, which are advertised as "high-energy vegetable concentrates". The newest product is Soylent Green - a small green wafer which is advertised as being produced from "high-energy plankton". It is much more nutritious and palatable than the red and yellow varieties, but it is in short supply, which often leads to riots.
Robert Thorn (Charlton Heston) is a New York City police detective who lives in a dilapidated, cramped one-room apartment with his aged partner Sol Roth (Edward G. Robinson). Roth is a former professor who searches through the now-disordered remnants of written records and books to help Thorn's investigations. Roth and his ilk are euphemistically known as "books". He tells Thorn about the times before the ecological disaster and population crisis, when real food was plentiful. (wikipedia)