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Max calories, minimum space?
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Tristana Rodriguez
(Tristana) - F
Max calories, minimum space? on 02/18/2013 07:03:26 MST Print View

Hi everyvone

As part of my bushcraft course we are doing a "40L challenge" - ie we can only pack 40L of stuff for the whole weekend.

In preparation , I thought I'd work out how many calories I got through this weekend (also bushcrafting) so I can try and make sure I don't end up ravenous. I'm already at 3876 and haven't added cups of tea or marg on bread/ potatoes yet . . . . I'm gonna need a bigger rucksack!

Any advice?

Ken T.
(kthompson) - MLife

Locale: All up in there
Re: Max calories, minimum space? on 02/18/2013 07:14:22 MST Print View

Well what do you have to eat so far? Any dietary restrictions?

What in your kit can you leave home for room for more food?

40l for a weekend should be easily doable.

Tristana Rodriguez
(Tristana) - F
hi on 02/18/2013 07:57:37 MST Print View


Well, preferably veggie. I will take a hammock, sleeping bag and tarp and as much warmth as possible. Fire not stove.

Travis Leanna
(T.L.) - MLife

Locale: Wisconsin
Re: hi on 02/18/2013 08:10:01 MST Print View

I agree with Ken. Maybe look at your other gear instead of food.

I've done a weekend with a 30L pack, and I'm sure others have done it with less.

What is your gear list?

Oh, and are you sure your pack is actually 40L? Often packs differ from their stated volume. For example, osprey might call a pack the XX40, but the small size might only be 38L, the medium 40L, and the large 42L.

Tristana Rodriguez
(Tristana) - F
Pack size on 02/18/2013 08:18:28 MST Print View

Thanks Travis

Well, the "challenge" is 40L - I don't have the back pack yet. I plan to make one out of a blue Ikea bag. Any tips on working out the capacity would also be very welcome!

Jeremy and Angela
(requiem) - F

Locale: Northern California
Re: Pack size on 02/18/2013 09:54:29 MST Print View

A liter is 1,000 cubic centimeters, e.g. a 10x10x10cm box. For USAnian units, a cubic foot is about 28.3 liters.

If you're making the pack perfectly cylindrical (or boxlike), the calculation is simple; for more complex shapes you may need to break them down into parts.

Tristana Rodriguez
(Tristana) - F
Oh! on 02/18/2013 09:55:56 MST Print View

Thanks Jeremy

I must've learnt that at school but it had completely evaded me!

Will get designing my pack then!

David Thomas
(DavidinKenai) - MLife

Locale: North Woods. Far North.
Measuring Pack size on 02/18/2013 09:56:18 MST Print View

If you use only hard objects to measure volume you will under-measure the pack: You'll measure a 40-liter pack as 35-ish liters. Or less

If you use 40 liters of loose lentils or rice, you'll get a very accurate volume, but that's a LOT of lentils (10.5 gallons).

If you combine the two techniques - rigid containers like 2-liter soda bottle, gallon milk jugs, and assorted Nalgene bottles with a few gallons or lentils, gravel or rice, you'll get an accurate measurement but minimize the amount of rice/lentils you use.

If you plan on doing this a lot, make some very floppy beanbags to hold the rice/lentils in 1-liter and 2-liter quantities to fill in the gaps around rigid containers without making a mess. Stitched out of cloth is sturdy and very flexible. A liter of rice in a gallon ziplock (burped of air) is quick and easy.

If I start one more sentence with the word "if" . . . .

David Thomas
(DavidinKenai) - MLife

Locale: North Woods. Far North.
Conversion factors, have I got conversion factors on 02/18/2013 10:07:07 MST Print View

Jeremy is right, 10 cm x 10 cm x 10 cm is a liter. A 40 liter pack might measure something like 20 cm deep x 80 cm tall x 25 cm wide = 40,000 cubic centimeters. Except a bag stitched from those sizes will be smaller due to seams. And a bag of that finished size will bulge out a little and actually hold more volume. Hence the ideas about lentil/rice beanbags.

Other handy facts:

There are 231 cubic inches in a gallon which is also = 3.8 liters. Plastic milk jugs are an example.

5-gallon fuel/water jerry cans are therefore 18 liters each - to their fill line. The whole container is more like 20 liters.

There are 1728 cubic inches (12 x 12 x 12) in a cubic foot which is also 28.3 liters.

40 liters = 40,000 cubic centimeters = 1.413 cubic feet = 2,442 cubic inches = 119 cans of beer (if there are no gaps between them).

Link .
(annapurna) - MLife
Re: Pack size on 02/18/2013 11:23:19 MST Print View

How to pack a 26 liter pack here , This is his various trips and lists.
Here is Cesars site,he does bushcraft also.
Tutorial videos for free.

Edited by annapurna on 02/18/2013 11:39:28 MST.

David Olsen

Locale: Steptoe Butte
lard on 02/18/2013 12:17:38 MST Print View

Ultra marathon racers in the north just bring lard. Cut off a slice and let it melt in your mouth as you run/bike/paddle etc.

Peanut butter for vegetarians.

David Olsen

Locale: Steptoe Butte
Re: Max calories, minimum space? on 02/18/2013 12:20:21 MST Print View

One overnight survival course I took allowed anything we could fit in a pepsi can. No fires. We chose to cram in several space blankets and poured sugar in to fill the empty spaces.

Pile'd up lots of pine needles, crawled in and spooned all night.

Edited by oware on 02/18/2013 12:24:13 MST.

Tristana Rodriguez
(Tristana) - F
tu on 02/18/2013 13:03:06 MST Print View

Thanks all

That has saved me some awkward maths!

Picked up some dried goods from the Chinese supermarket for tea (you don't see so much dried stuff in UK supermarkets) and made an experimental mushroom risotto. Not bad!

Booze was next on my list of considerations. spirits might be the most space efficient option but I do enjoy a cold beer after amp is set up!

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Conversion factors, have I got conversion factors on 02/18/2013 15:48:58 MST Print View

"5-gallon fuel/water jerry cans are therefore 18 liters each - to their fill line. The whole container is more like 20 liters."

David, you are mixing the internal volume dimensions with the external size dimensions. A jerry can that holds 5 gallons internally takes up more than 5 gallons of space.


Tom Kirchner
(ouzel) - MLife

Locale: Pacific Northwest/Sierra
Re: lard on 02/18/2013 17:05:16 MST Print View

"Peanut butter for vegetarians."

Or coconut oil/olive oil @ ~240-50 cal/oz. Also, there are many other high calorie nut butters available that provide a lot of calories in a very small amount of space; walnut, macadamia, cashew, and pecan come to mind.

Another approach would be to bring a relatively small amount of some high carb powder like maltodextrin, say 15-20 ounces, and use it to support the metabolism of body fat. If you're only out for a weekend, this would be a very effective way to cut down on the space required for food in your pack.

Tristana Rodriguez
(Tristana) - F
Running on empty on 02/19/2013 00:35:08 MST Print View

Thanks again all

But won't I still feel "empty" if I am not used to eating like that? ie. usually I'm used to consuming a greater volume of stuff.

Do I need to start practising?

Heather Hohnholz
(Hawke) - M
Eating high fat on 02/19/2013 07:32:27 MST Print View

Fat is actually the most satiating type of food. You will find your body will want to eat less of it. You will feel full more quickly. If you are used to eating high-carb, it will take you about a week or so for your body to get used to eating fats. You may experience stomach upset/diarrhea. If you do, up your fat intake slowly. A great way to start the switch is "Bulletproof Coffee." Your regular morning coffee with 2-4 Tb. of butter melted into it, hold the sugar. That's been my sole breakfast for a couple of months now, and it's great (although my days are pretty sedentary, it lasts me 3-4 hrs. 16oz coffee & 3T butter).

Tristana Rodriguez
(Tristana) - F
Butter on 02/19/2013 08:03:47 MST Print View

Thanks Heather

That's fascinating. Is there a vegan alternative to the butter?

I try to avoid dairy when I can!

Sarah Kirkconnell
(sarbar) - F

Locale: In the shadow of Mt. Rainier
Re: Butter on 02/19/2013 11:33:33 MST Print View

Yes, you can use coconut oil in most butter recipes - as long as your outside temps are below say 76*. There are also vegan margarines as well.
Frankly though, you can use olive oil in most recipes for hiking as well.

Hiking Malto
(gg-man) - F
Re: Re: lard on 02/19/2013 11:43:16 MST Print View

"Another approach would be to bring a relatively small amount of some high carb powder like maltodextrin, say 15-20 ounces, and use it to support the metabolism of body fat. If you're only out for a weekend, this would be a very effective way to cut down on the space required for food in your pack.".

Agree with this approach. I started off my UL backpacking thinking it was all about finding those higher calorie per ounce foods. I have since learned for short duration trips that I can carry a much lighter food load AND have more energy by carrying high carb foods and maximizing burning fat reserves.