BBC environment correspondent
One of the staple elements of armed forces kit bags - the operational ration pack - is being given a major facelift.
Soldiers will now be able to eat more global dishes
Designed to provide 24 hours worth of food for military personnel while in combat situations, the menu is being extended to include more global dishes - and to embrace healthy eating.
Rations have come a long way since they consisted of little more than cheese and hard biscuits.
There are now more than 27 different choices, designed to have a shelf life of at least three years and survive in extreme conditions.
Vegetarian, and halal options reflect the multi-ethnic make-up of today's armed forces.
But military experts admit the current packs are overly reliant on traditional meals like beef stew and dumplings, and so new dishes, including chicken balti with rice and meat balls with pasta, are being introduced.
There is also greater emphasis on good nutrition.
Military personnel are being encouraged to think of themselves as athletes, using their diet to speed recovery and reduce fatigue.
Isotonic drinks may be considered in the future.
However, RAF gunners acting as guinea pigs have given the new pack mixed reviews.
"If we are on exercise, we can be on these rations for four weeks or more," said Stewart, who with colleague Jay tried some chicken balti and rice in a clearing by a live firing range in Thetford, Norfolk.
"While it's nice to have a change from the old ones, you have no choice as to what you get to eat - sometimes you get the same food for weeks on end. The curry's not bad but you wouldn't want to eat it for a month."
The lightly spiced fruit biscuits get a better reception.
"Those with a cup of tea would be a welcome snack," said another gunner, Dean.
The general feeling about the chocolate brownie was it was very sweet and tasted like trench mud.
But one officer said: "After a day on manoeuvres in the arctic, you'd wolf that down in a minute."
Military personnel are quick to point out that the ration pack is only used in extreme combat situations - on general active service, a field kitchen would be established to provide fresh food.
Although food may seem a peripheral concern in times of active duty, defence staff emphasise that without a well fed army, navy or air force, you don't have an effective fighting force.
Getting food to the troops is one of the main logistical concerns.
Food also has a large part to play in morale and motivation.
That is why the British armed forces do their level best to ensure that wherever they are in the world, they tuck into Christmas lunch with all the trimmings - including crackers.
But as crackers are classed as explosives, there's a lot of paperwork that needs to travel with them.