Related Rule
Practice Relating to Rule 53. Starvation as a Method of Warfare
The Report on the Practice of Kuwait explains that it is the opinio juris of Kuwait that, during an armed conflict, the civilian population be able to maintain its “normal life” or at least “a minimum of normal life” and this includes the prohibition of the use of starvation as a method of warfare. 
Report on the Practice of Kuwait, 1997, Chapter 4.1.