|By Benjamin Gorelick
Food serves several purposes in the backcountry:
-Burn for energy
-Keeps us warm (in the energy burning process)
Where do we get our energy?
-Carbohydrates, Fats, and Proteins
Each is burned to give us energy, and we measure this energy in calories.
-Carbohydrates and Protein give us 4 calories per gram
-Fat gives 9 calories per gram
-Alcohol gives 7 calories per gram.
But backcountry nutrition is more than just counting an appropriate number of calories.
Your metabolism is like a fire. You've got to light it and get it going with kindling, then put on some small logs to get it to burn hotter, and then you can add some really big logs to keep it burning for a long time. Our bodies burn sugar/carbs most easily. It ignites fast (sugar rush) but it burns fast (sugar crash). Proteins are our small logs. They give the same amount of energy as carbs, but we burn them more slowly. And fats are like the big logs that hippies drag into the fire around midnight. They burn, but take a long time to do so. And burning them gives you lots of energy.
A few other notes:
-Our brains use sugar exclusively, and start to die without sugar in 4-6 minutes (see:
hypoglycemia in diabetics)
-Protiens are used and broken down to help the body fix itself. There are 22 amino
acids (building blocks of protien) needed to survive. We naturally make 12 of them, and need to ingest the other 10. They can be found in meat, some plant, and some bacteria sources.
-We also need numerous vitamins (vitamin k for blood clotting, b vitamins for numerous
uses) and minerals (potassium and salt play an important role in controlling brain and muscle function.
What does all this mean?
-We need to eat a diet balanced with carbs, fats, and protiens: 40% carbs, 30% protein, 30% fat by weight, more or less.
Next, let's go back and look at energy consumption. When you're doing more work or it's colder outside or, you need more energy (calories), as your body uses more energy to work and stay warm. Shivering, for example, is just involuntary exercise to keep burning energy, to keep releasing heat.
How many calories do you need per day?
-Men burn 1200 to 1400 cal per day doing nothing (lying in bed and watching CSI)
-Women burn 1100 to 1280 cal per day doing nothing (lying in bed and watching CSI: Miami)
Beyond this, the energy you need is dictated by exercise levels and muscle mass.
-1700 to 2000 total cal per day for most adults.
-2500 total cal for summer mountaineering
-3500 total cal for cool weather, hard work
-4000 total cal for cold weather and hard work
-8000 or more total cal for extreme athletes (Lance Armstrong)
So, let's say that we are going on a long mountaineering expedition in the spring. It'll be cool outside and we'll be doing lots of hard work. We want to eat about 4000 calories per day with a 40% carbs, 30% protien, and 30% fat. How much weight do we need to carry to get around 4000 calories?
It's pretty easy. We want 4000 calories per day, and we want 40% of that to come from carbs, 30% from protein, and 30% from fat. Let's do some math:
Carbs: 4000 cal * 40% = 1600 cal from carbs
Then we divide 1600 cal by 4 cal/g = 400g of carbs per day.
Protein: 4000 cal * 30% = 1200 cal from protein
1200 cal / 4 cal/g = 333 g of protein per day.
Fat: 4000 cal * 30% = 1200 cal from fat
1200 cal / 9 cal/g = 133 g of fat.
Add it up, and we have 866g of food per person per day to get 4000 calories.
Next, we need to break this down into meals, breakfast, lunch, and dinner. We need 400g of carbs total during the day. If we break things down evenly, that means we should have 133g with breakfast, 133g with lunch, and 133g with dinner. We would have 111g of protein and 44g of fat with each meal as well, for a total of 288g of food with each meal (again, for a total of 866g for the day).
But it's a bit more complicated than that. Have you ever eaten a huge breakfast and then tried to go for a run? It sucks. Your body is spending all that energy trying to digest your food, so you don't have any extra energy to exercise. If you try, you'll be slower than usual. You might even throw up.
Therefore, in the mountains, we don't just eat 3 equal, square meals during the day. Breakfast tends to be quick, while we "graze" during the day, having a bit of lunch at each break. Then dinner is whatever is a bit smaller than lunch. So I'll probably eat 30% of my food for the day at breakfast, 40% of my food for the day at lunch, and the final 30% at dinner.
That means I'll have a 260g breakfast, a 346g lunch, and a 260g dinner. That's still 866g total, but I'm dividing it out more efficiently for my body to use during the day.
And it gets more complicated still. Remember the fire analogy I gave at the beginning? Good. When you wake up in the morning, your metabolic fire has had all night to burn down. We're on embers now, and we need to get our fire re-stoked. What kind of wood do we want to burn to do that? Kindling. So for breakfast, we need a bit more sugar.
During the day, we want a diet that will burn at a constant rate. We don't want any highs or lows. So we need to eat a bit more protein. And for dinner, we're getting ready to go to bed for the night, so we want something that will burn all night long and keep us warm. Cleverly, that's fat, so we'll go a bit heavier on fat at night.
If your head is about to explode, don't worry. Here is a spread sheet to do it all that.
All you have to do is plug a few numbers in (how many people in your group, how many days you're going out for, and how many calories you want per person per day, and it'll give you a shopping list, a packing list, and even a cost. Cool, eh?
But it's also important to know how to do this, so here's the math on how the above ration plan would work out for a 4000 calorie day.
Breakfast is 30% of our total calories (4000) for the day, so we want 1200 calories for breakfast. At our normal 40% carbs, 30% protein, 30% fat balance, that would give us
1200 cal * .4 = 480 calories from carbs. Then divide 480 calories by 4 calories/gram, and you get 120g of carbs.
For protien (30% of our calories), we get:
1200 cal * .3 = 360 calories from protein. Then divide 360 calories by 4 calories/gram, and you get 90g of protein.
And for fats (30% of our calories), we get:
1200 cal * .2 = 360 calories from fat. Then divide 360 calories by 9 calories/gram, and you get 40g of fat.
So for breakfast, we want to eat 120g of carbs, 90g of protein, and 40g of fat. That's 250g total for breakfast.
But I want to shift a few calories from fats (big, slow to burn logs) to carbs (kindling). So I'll add an extra 20g of carbs (80 calories), and take away 9g of fat (81 calories) to breakfast. So my final numbers for breakfast are:
1200 calories total
I would do the opposite shift for dinner, when I want a nice, slow burning log (fat) to help keep me warm all night long.
You can do the math on your own, like the above or you can trust me when I tell you that you'll want:
1600 cal total
1200 cal total
Pshew, that's a lot of math.
Anyway, there's one more step to the process. And that's figuring out what we actually want to eat. Luckily, this is pretty easy.
I'll do breakfast as an example:
First, let's make three lists. One list will be things that we like to eat for breakfast that are carbohydrates. The second will be things that we like to eat for breakfast that are protein. The third will be things that we like to eat for breakfast that we like to eat that are fats.
On the first list, we might include oatmeal, bagels, granola, hash brown potatoes, and so forth.
On the second list, we might have nuts, bacon, and salami.
On the third list, we might have peanut butter, butter, cheese, and so forth. You get the idea.
Next, from the above, for breakfast we want to have 140g of carbs per person per day, 90g of protein per person per day, and 31g of fat per person per day.
Let's use some nice, easy numbers and say that we're 2 people who are going for a 5 day trip. That means that, for the entire trip, we need:
140g of carbs per person per day * 2 people * 5 days. That's 1400g of breakfast carbs.
90g of protein per person per day * 2 people * 5 days = 900g breakfast protein.
31g of fat per person per day * 2 people * 5 days = 310g of breakfast fats.
Then we go back to our list of food we like. For breakfast carbs, we said that we can bring oatmeal, bagels, granola, or hash brown potatoes. We now know that we need to bring 1400g total of the stuff, so I'll assign some numbers to each that total 1400g. I hate oatmeal, so I won't bring any of that. But I like bagels, so I'll bring 700g of bagels, 350g of granola, and 350g of hash brown potatoes.
I'd do the same for proteins:
And for fats:
150g peanut butter
Do the same thing for lunch and dinner, and, voila, you have a nutritionally balanced diet for multiple people for multiple days. Easy, right?