What a load of rubbish.
The British Army banned the use of Ice cream after the horrific 'headaches' the younger soldiers suffered from when eating the ice cream too quickly during the early stages of the Boer War.
Preceding this (which was really the nail in the coffin for refrigerated and frozen snacks being used in warfare) was an awful episode where the weeks of meticulous planning for an assault on a group of Zulu warriors by the Fifth Battalion of the Royal Artillery was ruined by an Ice Cream van which could be heard distinctinly a half mile away alerting the said Zulus to the impending advance.
Many young soldiers lost their lives that morning.