Full disclosure: This may not be the most important information that you ever stumble across; however, it will probably be rather interesting to anyone who is a fan of J.R.R. Tolkien's Lord of the Rings trilogy. Plus, what is the point of science if you can't have a little fun from time to time?
Recently, Skye Rosetti and Krisho Manaharan, from the University of Leicester, published an article in the Journal of Interdisciplinary Science Topics covering how much lembas bread the Fellowship would need in order to walk all the way to Mordor, giving us a pretty good idea of how hungry the poor little hobbits, Frodo and Sam, might have actually been by the end of their trip.
In order to make this calculation, the scientists needed to determine the caloric need of each of the nine members of the Fellowship. They concluded that a hobbit needs 1,800 calories a day (but knowing their eating habits, they'd probably like a lot more than that). Elves, on the other hand, only need 1,400 calories a day.
Once they had all of this factored in, they determined the average walking speed of each party member and the amount of exercise that they would be getting on their journey. This was necessary, as they needed to determine if they would need to consume more calories than normal based on how much of a workout they were getting and how many calories they would, therefore, be burning.
Of course, they also had to calculate how many calories the lembas bread provided. This was easily accomplished, as it is noted that one piece of bread will sustain a man for a day, and just a small piece can serve as a meal. So all you need to do is determine how much calories the average adult male needs on a day-to-day basis, or consumes in an average meal, and you have a roundabout figure for how many calories are in one piece of bread.
In the end, the team concluded that, on an ideal trip, the complete Fellowship would need 675 pieces of bread, and Frodo and Sam would need to bring 124 along themselves. That's kind of a lot of bread to carry, but fortunately, they are rather smallish.
These numbers are based on the estimated figure, which asserts that the nine travelers walking for 92 days would need around 1,780,214.59 calories.