Leaving aside my strong feelings about the deceptions in Ed Wardle's dieting show, "Alone in the Wild: One Man's Adventure At Avoiding Food and People at the Lodge" I thought some of you might be interested in some of the calorie math issues that pop up surviving in the arctic.
This will be two long posts, but if you want to examine the kinds of things those of us who actually do go out into the arctic/subarctic worry about, read on.
For all intents and purposes, anyone who is placed alone in the arctic or subarctic without resupply over a reasonable duration will die. Even Ray Mears.
Sure there are some examples of people surviving, but they're the statistical flukes and generally had extraordinary luck.
I'm talking about the other 99% of the time here -- a lone person will die. There is a reason even the natives don't go out alone for a long time.
You need a party to survive up there. If you're alone, you inevitably wind up in a meaningful calorie deficit that will kill you over time.
This post explains the hard facts of calories in the subarctic.
First off, we know the basal metabolism of an individual in a temperate clime.
I'm going to use men for this calculation and women burn fewer calories in basal metabolism. I'm not being sexist here, I just don't want to do the calculations twice... but hang on gals, your enormous virtues in the wild will appear toward the end. Also, sorry, but I'm not doing the metric conversions here...
The basal metabolism calculation in a temperate zone is:
66 + (6.3 x body weight in pounds) + (12.9 x height in inches) - (6.8 x age in years)
A 5' 10'' male, who is 35 years old and weighs 165 pounds has a basal metabolism of 1,770 calories per day. If he consume less than that, he starts losing weight.
Of course the basal number in the arctic is close to 2,500 for this hypothetical man, but again, we'll use the lower number to give poor old Ray Mears the best chance possible.
The reality of life in the wild is that the camp chores that exist for one person are more or less the same as those for a group of people. You use the same amount of firewood, etc.
Maybe the shelter is a little larger, but not appreciably. Yes, you have to gather a bit more water, but not enough to radically change the calorie burn.
So here is the calorie burn for different activities in a northern clime (established by thermographic studies --- I've collected these over the years because this stuff matters to me when planning trips...)
Activity and hourly calorie burn:
Chopping/gathering wood: 500
tending camp (odd jobs, mending shelter, etc.): 240
If you don't bring food in, these are daily tasks. So here is a reasonable expectation for the average number of hours a day that you will need to perform each task, along with the daily total calorie burn:
Chopping/gathering wood: 2 hours, 1000 calories
Tending camp (odd jobs, etc.) 2 hours, 480 calories
Hunting: 4.5 hours, 1800 calories
Foraging: 3 hours, 1020 calories
Total daily calorie needs for camp related activities: 4300 calories per day.
Total camp activities + basal metabolism for 1 person: 6,070 calories per day.
(Notice that about half of your calories are expended on acquiring food – that percentage matters later...)
Now I want to stress that's the best case with decent weather, etc for a fit individual. It's not uncommon to see backpackers who burn 8,000-10,000 calories a day in this environment.
Which brings us to the question of what happens on the move. The above calculations are for a stationary person. What happens if you break camp and go?
Assume a total weight of camping gear (excluding clothes and food) of 30 pounds. That would be light for some folks, heavy for others. But we're also assuming that you're carrying a rifle for hunting, so at ~ 7.5 pounds for the gun without ammo, that leaves you with 22.5 pounds for all the rest of your gear.
If you carry that and nothing else, you'll burn 1596 calories on a 4 hour hike.
By the time you add clothes and ammo and food, you're carry more. But again, let's offer the best case: 1596 calories for a 4 hour hike over reasonable terrain. (What you'll face in much of Alaska would have you burning about twice that much in the real world...)
Here's where things get interesting: a single person who is stationary needs about 6070 calories a day in camp and about 7,666 if hiking (remember, you've still got all the camp chores even if you're on the move.)
So how much food will that person require.
I'll focus entirely on meat because protein and fats are crucial in this equation. Here is the calorie value for one pound of meat of various northern game:
Venison (Sitka deer): 480
Bear (late season): 1173
You can see why bears prize fish -- it's a huge benefit for protein and fat. You can also see why bear makes good survival meat late in the season.
OK, let's assume than an individual requires the 4300 calories a day for CAMP CHORES ONLY. To accomplish that you would have to acquire:
4.8 pounds of Salmon per day or..
4.9 pounds of Trout per day or....
8.9 pounds of venison per day or...
7 pounds of moose per day or...
3.6 pounds of bear per day or...
5.4 pounds of rabbit per day
That's a LOT of food to get every day, because you have to do this regardless of the season... And that's the amount you need in a fixed camp -- on the move you need a lot more...
And even if you got these amounts, your basal metabolism will put you in a deficit and you'll lose from 1/2 to 3/4 of a pound a day.
Over 30 days of this, you could lose up to 22 pounds. And that's the best case. Real world, you're looking at losing closer to 35 pounds EVEN IF you get the amount of game listed above!
If you're lucky and you bag a bear or a moose early on, you might be OK for a little while. But, well, that requires a lot of luck. And if you're on the move, you've got to transport all that meat, preserve it, etc....
And what if you're not lucky?
A pound of human fat contains about 3,500 calories. So if you don't acquire any food, you're looking at losing about 2 pounds a DAY of weight.
(This is a little tricky because of fitness issues, but it's a fairly accurate general rule.)
If you're backpacking and covering miles, the typical rule of thumb is you need to carry 30 pounds of food a week. Few backpackers actually carry that much because, well, as you can see traveling lighter is better from a calorie burn perspective. In general though, you figure to lose 1/2 to 1 pound per day backpacking on trips longer than a week.
Good diet plan.
So here's the problem: an individual has to have enormous luck hunting to acquire the food necessary to get through a single day's activities and maintain weight.
If you have bad luck for ONE DAY, you lose almost 2 pounds. If you have bad luck for 2 days a week and good luck the rest of the time, you're still losing 4 pounds a week.
Of course, that kind of loss will make other chores harder. You're feeling real energy drain, lethargy, if you don't have enough protein you won't think straight, etc.
And over time, that kills you. Guaranteed. Even if you're Ray Mears alone in the arctic, you die over time. Because even good old sainted Ray won't be lucky hunting every day....
But what happens if you have a party along? The situation changes substantially... That will be the subject of the next post in this thread. I'll have it up in a couple of minutes