K-Rations (images and notes from wikipedia:
Breakfast Unit: canned entrée veal (early version), canned chopped ham and
eggs (all subsequent versions), biscuits, dextrose or malted milk tablets
(early version), dried fruit bar, pre-mixed oatmeal cereal (late version),
halazone water purification tablets, a four-pack of cigarettes, Dentyne or
Wrigley chewing gum, instant coffee, a packet of toilet paper tissues, and sugar
(granulated, cubed, or compressed).
Dinner Unit: canned entrée pork luncheon meat (early version), canned
processed American cheese, Swiss and American cheese, or bacon and cheese
(cheese entrée all subsequent versions), biscuits, 15 dextrose or malted milk
(diastatic malt) tablets (early) or five caramels (late), sugar (granulated,
cubed, or compressed), salt packet, a four-pack of cigarettes and a matchbook,
chewing gum, and a powdered beverage packet (lemon (c. 1940), orange (c. 1943),
or grape (c. 1945) flavor).
Supper Unit: canned meat, consisting of cervelat sausage (early version),
either pork luncheon meat with carrot or apple (first issue), beef and pork loaf
(second issue); biscuits; a 2-ounce (57 g) D ration emergency chocolate bar
(early version), Tropical bar, or (in temperate climates) commercial sweet chocolate
bar (late version), a packet of toilet paper tissues; a four-pack of cigarettes,
chewing gum, and a bouillon packet (cube or powder).
In total three meals provided 2,830 kilocalories (11,800 kilojoules) of food
energy and 79 grams of protein, depending upon components. As it was
originally intended as an "assault" ration to be issued for short durations,
the K-ration was designed to be used for a maximum of 15 meals. The K-ration
was mass-produced by several major U.S. food production companies, including
H. J. Heinz, Patten Food Products Company and The Cracker Jack Company.