Far be it from us to question the wisdom of Gandalf the Grey, but what exactly qualifies a hobbit for a lengthy, dangerous trek across Middle Earth? Their nimbleness and temperament aside, are they even healthy enough for adventuring?
In his classic adventure tale "The Hobbit," originally published in 1938 and never out of print, J.R.R. Tolkien introduced the diminutive race. He described hobbits as "a little people, about half our height" who preserved an "ancestral habit of living in tunnels and holes." They tended to be solitary and portly, which seems reasonable given their penchant for pipe-weed, ale and a staggering six meals per day. Sure, they were accomplished hiders, but little else seemed to qualify halflings for cross-continental travel and frequent monster encounters.
Clearly, the wizard Gandalf didn't require Bilbo (or his cousin Frodo, whom he also recruited) to pass a pre-adventuring physical. But if we force our modern understanding of health and biology on the people of the Shire, what can we determine? A few contemporary scientists and researchers have been kind enough to offer their speculative interpretations of hobbit physiology.
Metabolism of the Hobbit
For starters, let's consider those six daily meals. Is this the lifestyle of a burrowing glutton, or proper caloric intake for a halfling? In 2015, Krisho Manoharan and Skye Rosetti of the University of Leicester Centre for Interdisciplinary Science weighed in on the issue with their paper "Modelling the BMR of Species in Middle-Earth."
Manoharan and Rosetti set out to determine the base metabolic rate (BMR) for the elves and hobbits of Middle Earth — if those humanoid species were actually real, of course. In other words, they set out to gauge the amount of energy their bodies need to function at rest. They did this by modeling each race as a mammalian Earth species. The European roe deer (Capreolus capreolus) stood in for the forest-dwelling elves. The hobbit, being a burrowing, hole-dwelling people, was stuck with the Southwestern pygmy possum (Cercartetus concinnus).
The authors concluded that hobbits would have boasted a BMR of 1818.7 kilocalories every day, this compared to 1702.2 kilocalories every six days for humans (or "men" in Tolkien's writings) and 1416.5 kilocalories every five days for elves. As such, they figured the average hobbit would require 6.7 meals per day. Indeed, that's in keeping with the higher energy demands of smaller birds and mammals.
In a follow-up paper, Manoharan and Rosetti concluded that a single hobbit would require 76 pieces of elven lembas bread to march from Imraldis to Mount Doom, as happens in "The Lord of the Rings" trilogy that followed "The Hobbit." That amount compared with 99 for a dwarf, 60 for an elf and 71 for men. As such, the nine members of the fellowship of the ring would require 675 pieces of lembas, with 304 pieces allotted to the four hobbit members.
Appetite for Adventuring
In Tolkien's "The Hobbit," Bilbo Baggins often complains of fatigue. He also pines for a more robust meal schedule — as do some of his dwarven traveling companions. Still, he manages to get by on less.
"(Meals) didn't come quite as often as Bilbo would have liked them," Tolkien writes, "but still he began to feel that adventures were not so bad after all."
When meals did present themselves, however, Bilbo was all in on whatever was offered, be it cream and honey provided by a vegetarian werebear, or mere sorrel and berries scavenged in the mountain wilds. He dreamt of bacon and eggs, but could subsist on seemingly anything — and this may illustrate another key adventuring advantage for the halfling species: a varied omnivorous diet.
A Hobbit in the Sun
As Dr. Joseph A. Hopkinson and son Nicholas S. Hopkinson argue in their Medical Journal of Australia paper "The hobbit — an unexpected deficiency," the sort of diet would be a key advantage considering the hobbit's subterranean tendencies. Because to live away from the sun is to cut yourself of from a key source of vitamin D. The so-called "sunshine" vitamin is crucial for skeletal health and the immune system, with deficiency symptoms ranging from depression and weakness to increased bone fragility.
Fortunately, you can obtain vitamin D from various foods, such as oily fish (which benefits the subterranean, former-hobbit Gollum). Bilbo's diverse diet and willingness to travel long distances in the sun, the Hopkinsons argue, not only boosts his vitamin D intake but also makes the hobbit species one of Middle Earth's top vitamin D consumers.
Based on the text of "The Hobbit," the researchers assigned major Middle Earth species and individuals a vitamin D score between zero and four. Hobbits, men and high elves topped the list with fours, dwarves scored a three and Gollum a lowly one. The evil species of Middle Earth (dragons, goblins and trolls) all scored zeros.
The Hopkinsons go so far as to argue that vitamin D consumption might serve as a decent predictor of victory in Middle Earth — alongside moral attributes and martial prowess. (Face it, Sauron, your orc hordes will only get so far with gloomy dispositions and brittle bones.)
So perhaps Gandalf indeed saw something special in hobbits: a high-metabolism creature with a varied diet, able to march across Middle Earth's varied ecosystem and eat whatever they could find.
Dr. Hopkinson had previously studied the effects of vitamin D in people with lung disease, and is not a fan of all the wizard and hobbit smoking. Reached for comment, he provided some advice for any sunshine-avoidant hobbits out there looking to stay healthy.
"The best and briefest health advice is to eat less and move more," Hopkinson tells HowStuffWorks. "Adventures are one way to achieve this, though maybe not the safest. As Bilbo says, 'Adventures are not all pony-rides in May-sunshine.'"