Post by RumiDude on Jun 1, 2019 17:39:53 GMT -8
Sometimes you read something and it just clicks as too just how useful the information is. Just recently I read a blog post about calculating food weight that seemed to make soooooo much sense I wondered why I had never read it before. Then I wondered why I hadn't thought of it myself. So here it is ...
First thing to do is to figure the Calorie density of food. To do that you divide the calories per serving by the weight per serving. This will give you the Caloric density of the food, i.e. the Calories per ounce or gram. For example nuts are Calorie dense. A serving of dry roasted almonds are 170 Calories per 1 ounce or 168 calories per 28 grams. That yields a Caloric density of 170C/oz or 6C/g. Compare that to say Pop-Tarts. A Strawberry Pop-Tart serving is 50 grams (aprox 1.78 oz) and has 180 Calories. It's Caloric density is just 3.6C/g or 101.2C/oz. That is the idea of Caloric density and how to properly evaluate and compare foods.
Now next thing to figure is how many calories you need per day. A general rule of thumb is during a regular day and adult needs about 2000 Calories. Of course that widely varies. But on a backpacking trip you need more than 2000 Calories. In order to keep from bonking, a backpacker need mores the more miles and elevation gain/loss they cover per day. A weekend warrior only doing 5-7 miles on moderate terrain may only need 3000-3500 calories per day. A long distant thru hiker may need anywhere from 4500 to 5500 Calories per day. It is difficult to estimate this without actually tracking things. If only out for two or three days, a hiker can often get by on their own fat stores and not increase their Caloric intake much at all. Indeed, many hikers face that feeling of not wanting to eat on just the first day or two. But if faced with difficult terrain and mileage, most hikers can't rely on using their fat stores to kick in and usually bonk if they don't eat significantly. Additionally hikers out for longer periods find that eventually their fat stores just aren't enough to stave off fatigue and lethargy. I have always figured it is better to have more food than not enough.
The third thing to figure is how much food one is willing to carry for each day's consumption. The old rule of thumb was 2 pounds of food per day. Others have argued that 1.5 pounds per day is sufficient. The longer the trip is the more food one needs. On my recent trip in the Grand Canyon, we were out for eight days. In the thread about the longest trip without resupply, my longest was 14 days. That was a hellacious burden of food to carry. For eight days in the Grand Canyon I think my food weighed about 15 pounds.
Anyway, with all that figured up, the final step is to put it all together to determine the average Caloric density of one's food in order to reach both Caloric needs as well as limit the weight of food one is comfortable carrying. On trips of 2-4 days I usually don't even worry about that and just take what I want. But going out longer requires more thoughtful consideration. The longer one is out the more Calorie dense the food needs to be in order to not become overwhelmed by food weight. Here is the calculation: Food Calories per Day ÷ Weight of Food (either in ounces or grams) = Average Caloric Density. So if one were only going to carry 1.5 lbs (24 oz) of food per day and needed 3500 calories, that would require foods to be an average of 145 C/oz or 5 C/g. Carrying 2 lbs (32 oz) of food per day would require foods to be an average of 109.37 C/oz or 3.9 C/g. You can see if the Calories required per day goes to 4000, 4500, 5000, and up, the average Caloric density must increase as well. This is significant for long distant thru-hikers who may need 5000 calories per day.
Anyway, I thought I would share this. I understood it in an abstract big picture sorta way, but never saw it actually calculated and explained. I found this information here on a blog on The Trek. Actually I originally found info related on a FaceBook group I am on which led me to Backcountry Foodie. She is a dietitian and backcountry adventurer and athlete.
Rumi~the hungry~Dude
First thing to do is to figure the Calorie density of food. To do that you divide the calories per serving by the weight per serving. This will give you the Caloric density of the food, i.e. the Calories per ounce or gram. For example nuts are Calorie dense. A serving of dry roasted almonds are 170 Calories per 1 ounce or 168 calories per 28 grams. That yields a Caloric density of 170C/oz or 6C/g. Compare that to say Pop-Tarts. A Strawberry Pop-Tart serving is 50 grams (aprox 1.78 oz) and has 180 Calories. It's Caloric density is just 3.6C/g or 101.2C/oz. That is the idea of Caloric density and how to properly evaluate and compare foods.
Now next thing to figure is how many calories you need per day. A general rule of thumb is during a regular day and adult needs about 2000 Calories. Of course that widely varies. But on a backpacking trip you need more than 2000 Calories. In order to keep from bonking, a backpacker need mores the more miles and elevation gain/loss they cover per day. A weekend warrior only doing 5-7 miles on moderate terrain may only need 3000-3500 calories per day. A long distant thru hiker may need anywhere from 4500 to 5500 Calories per day. It is difficult to estimate this without actually tracking things. If only out for two or three days, a hiker can often get by on their own fat stores and not increase their Caloric intake much at all. Indeed, many hikers face that feeling of not wanting to eat on just the first day or two. But if faced with difficult terrain and mileage, most hikers can't rely on using their fat stores to kick in and usually bonk if they don't eat significantly. Additionally hikers out for longer periods find that eventually their fat stores just aren't enough to stave off fatigue and lethargy. I have always figured it is better to have more food than not enough.
The third thing to figure is how much food one is willing to carry for each day's consumption. The old rule of thumb was 2 pounds of food per day. Others have argued that 1.5 pounds per day is sufficient. The longer the trip is the more food one needs. On my recent trip in the Grand Canyon, we were out for eight days. In the thread about the longest trip without resupply, my longest was 14 days. That was a hellacious burden of food to carry. For eight days in the Grand Canyon I think my food weighed about 15 pounds.
Anyway, with all that figured up, the final step is to put it all together to determine the average Caloric density of one's food in order to reach both Caloric needs as well as limit the weight of food one is comfortable carrying. On trips of 2-4 days I usually don't even worry about that and just take what I want. But going out longer requires more thoughtful consideration. The longer one is out the more Calorie dense the food needs to be in order to not become overwhelmed by food weight. Here is the calculation: Food Calories per Day ÷ Weight of Food (either in ounces or grams) = Average Caloric Density. So if one were only going to carry 1.5 lbs (24 oz) of food per day and needed 3500 calories, that would require foods to be an average of 145 C/oz or 5 C/g. Carrying 2 lbs (32 oz) of food per day would require foods to be an average of 109.37 C/oz or 3.9 C/g. You can see if the Calories required per day goes to 4000, 4500, 5000, and up, the average Caloric density must increase as well. This is significant for long distant thru-hikers who may need 5000 calories per day.
Anyway, I thought I would share this. I understood it in an abstract big picture sorta way, but never saw it actually calculated and explained. I found this information here on a blog on The Trek. Actually I originally found info related on a FaceBook group I am on which led me to Backcountry Foodie. She is a dietitian and backcountry adventurer and athlete.
Rumi~the hungry~Dude
