The Meal, Ready-to-Eat — commonly known as the MRE — is a self-contained, individual field ration in lightweight packaging bought by the United States military for its service members for use in combat or other field conditions where organized food facilities are not available. The MRE replaced the canned MCI or Meal, Combat, Individual rations in 1981 and is the intended successor to the lighter LRP ration developed by theUnited States Army for Special Forces and Ranger patrol units in Vietnam.

Each meal provides about 1,200 Calories and has a shelf life of three years (depending on storage conditions).

Each MRE weighs 510 to 740 grams (18 to 26 oz), depending on the menu. Since MREs contain water, they weigh more than freeze-dried meals providing equivalent calories.The companies that produce the military MREs are not allowed to sell them to the general public. However, they can still be found for sale by individuals. You can also buy civilian MRE's that are readily available or make your own.

General contents may include:

Entree - the main course, such as Spaghetti or Beef Stew
Side dish - rice, corn, fruit, or mashed potatoes, etc.
Cracker or Bread
Spread - peanut butter, jelly, or cheese spread
Dessert - cookies or pound cakes
Candy - M&Ms, Skittles, or Tootsie Rolls
Beverages - Gatorade-like drink mixes, cocoa, dairy shakes, coffee, tea
Hot sauce or seasoning - in some MREs
Flameless Ration Heater - to heat up the entree
Accessories - spoon, matches, creamer, sugar, salt, chewing gum, toilet paper, etc.
How does an MRE heater work?

A flameless heater uses the oxidation of a metal to generate heat. Magnesium metal works best because it rusts much more quickly.

To make a flameless heater, magnesium dust is mixed with salt and a little iron dust in a thin, flexible pad about the size of a playing card. To activate the heater, a soldier adds a little water. Within seconds the flameless heater reaches the boiling point and is bubbling and steaming.

To heat the meal, the soldier simply inserts the heater and the MRE pouch back in the box that the pouch came in. Ten minutes later, dinner is served!

The MRE has led to the creation of several similar field rations.

For servicemembers with strict religious dietary requirements, the military offers the specialized Meal, Religious, Kosher/Halal. These are tailored to provide the same nutritional content, but will not contain offending ingredients.There is also a special meal certified for passover requirements.

The Humanitarian daily ration is a self-contained Halal meal designed to be given to refugees and other displaced people. It is designed to feed a single person for a full day, and the menus were intended to be palatable to many religious and cultural tastes around the globe. It is created and packaged much like MREs.

The Meal, Cold Weather provides a ration similar to the MRE designed for lower temperatures than the MRE can withstand. Clad in white packaging, it offers a freeze-dried entree designed to be eaten with heated water, the same side ingredients as the standard MRE, and additional drink mixes to encourage additional hydration. The MCW replaced the Ration, Cold Weather.

The Meal, Long Range Patrol is essentially the same as the MCW, but with different accessory packs. The MLRP is designed for troops who may receive limited or no resupply, and weight of the ration is critical. The similar First Strike Ration is along the same lines, but requires no preparation and may be eaten on the go.

The Tailored Operational Training Meal provides a lower calorie count for less intensive training environments, such as classroom instruction. The TOTM allows troops to become familiar with the MRE and its contents without providing an excessive amount of calories to troops who will not necessarily burn them.

The Unitized Group Ration is a ration much like the MRE, but expanded to feed large groups.The Food Packet, Survival, General Purpose, Improved is given to pilots and other servicemembers that may require a small, extremely portable food ration for emergency situations. It contains food bars and a drink mix.Similarly, the Food Packet, Survival, Abandon Ship and Food Packet, Survival, Aircraft, Life Raft are fitted into the storage areas on lifeboats.