Related Rule
Belgium
Practice Relating to Rule 53. Starvation as a Method of Warfare
Belgium’s Law of War Manual (1983) states that “starvation as a method of warfare against civilians” is prohibited. 
Belgium, Droit Pénal et Disciplinaire Militaire et Droit de la Guerre, Deuxième Partie, Droit de la Guerre, Ecole Royale Militaire, par J. Maes, Chargé de cours, Avocat-général près la Cour Militaire, D/1983/1187/029, 1983, p. 28.
Belgium’s Penal Code (1867), as amended in 2003, provides:
War crimes envisaged in the 1949 [Geneva] Conventions … and in the [1977 Additional Protocols I and II] … , as well as in Article 8(2)(f) of the [1998 ICC Statute], and listed below, … constitute crimes under international law and shall be punished in accordance with the provisions of the present title … :
10. intentionally using starvation of civilians as a method of warfare, by depriving them of objects indispensable to their survival, including by wilfully impeding relief supplies as envisaged in the [1949] Geneva Conventions. 
Belgium, Penal Code, 1867, as amended on 5 August 2003, Chapter III, Title I bis, Article 136 quater, § 1(10).
Belgium’s Law relating to the Repression of Grave Breaches of International Humanitarian Law (1993), as amended in 2003, provides:
War crimes envisaged in the 1949 [Geneva] Conventions … and in the [1977 Additional Protocols I and II] … , as well as in Article 8(2)(f) of the [1998 ICC Statute], and listed below, … constitute crimes under international law and shall be punished in accordance with the provisions of the present title … :
6 bis intentionally using starvation of civilians as a method of warfare, by depriving them of objects indispensable to their survival, including by wilfully impeding relief supplies as envisaged in the [1949] Geneva Conventions. 
Belgium, Law relating to the Repression of Grave Breaches of International Humanitarian Law, 1993, as amended on 23 April 2003, Article 1 ter, § 1(6 bis).
In 1969, in a statement before the UN General Assembly, the Belgian Minister of Foreign Affairs condemned methods of warfare that led to the starvation of civilians in the context of the Nigerian civil war. 
Belgium, Statement by the Minister of Foreign Affairs before the UN General Assembly, UN Doc. A/PV.1765, 25 September 1969, §§ 132–133.
At the CDDH, Belgium qualified Article 48 of the draft Additional Protocol I (now Article 54) as “a step forward in the development of humanitarian law”. 
Belgium, Statement at the CDDH, Official Records, Vol. XIV, CDDH/III/SR.31, 14 March 1975, p. 307, § 53.
The Report on the Practice of Belgium states that Belgium demonstrated support for the prohibition of starvation in international and non-international armed conflicts even before the adoption of the Additional Protocols in 1977. 
Report on the Practice of Belgium, 1997, Chapter 4.1.