(Image: New Line Cinema)
In The Lord of the Rings, lembas is a special bread made by elves. It's a compact, nutritious food. When eaten thriftily, a small portion can sustain a person for a long period of time. It won't spoil when wrapped in certain leaves. Consequently, it's the perfect trail ration.
The elves of Lothlórien gave lembas to the Fellowship to help the march through the barren land of Mordor on their way to destroy the One Ring. How much would they have needed for the journey if they ate nothing but lembas? Skye Rosetti and Krisho Manaharan of the University of Leicester published a paper in the Journal of Interdisciplinary Science Topics on the subject. They concluded:
For an ideal journey with all 9 members of the fellowship, using the metabolic rates for each species from [2], the total calorific consumption of the 92-day journey was found to be 1,780,214.59 kcal. If the elves of Imraldis had provided the Fellowship with lembas, this would equate to them having to carry a total of 675 pieces, or 75 pieces each. For the different species, this equates to 304 for the hobbits, 214 for Gandalf, Aragorn and Boromir; 99 for Gimli and 60 for Legolas.
-via VA Viper