Isaf commanders say the priority is to get supplies to troops
Burger bars and pizza joints in Nato bases across Afghanistan are being closed down in an effort "to increase efficiency across the battlefield".
A Nato spokesman said that "amenities" at bases across the country are being phased out for logistical reasons.
He said officials at each base will decide exactly when they are axed.
Nato's top Afghanistan commander, Gen Stanley McChrystal, made it clear last year that the days of Burger King and Pizza Hut on Isaf bases were numbered.
He expressed concern that burger bars, pizza restaurants and other stores in large International Security Assistance Force (Isaf) bases at Kandahar, Bagram and Mazar-e-Sharif served as a distraction to the military mission.
"For several months now we have been in the process of bringing 39,000 extra troops to Afghanistan - in addition to extra equipment, ammunition and supplies," the Nato spokesman told the BBC.
"Soldiers will still be able to eat pizzas and burgers - but served up in military canteens rather than in commercial outlets."
The aim is to 'optimise' efficiency at bases like Bagram
A blog written in February by a senior Isaf morale welfare and recreation officer states the argument bluntly for closing down outlets such as Burger King, Pizza Hut and Dairy Queen.
"This is a warzone, not an amusement park," the blog written by Command Sgt Maj Michael T Hall says.
"In order to accommodate the troop increase and get refocussed on the mission in hand, we need to cut back on some of the non-essentials.
"Supplying non-essential luxuries to big bases like Bagram and Kandahar makes it harder to get essential items to combat outposts and forward operating bases, where troops fighting every day need to be resupplied with ammunition, food and water."
Command Sgt Maj Hall said that closing such outlets will free up much needed storage space and reduce the amount of flight and ground convoy traffic across Afghanistan.
He said it would also free up "water and electricity needs required to run these businesses".
Correspondents say that while the closures are not likely to bother troops on the frontline who live in tough conditions, many in the larger bases on lengthy 12-month tours may complain it places an added burden on them.