Dietary intake

[Lophophaps]

Advice is sought on food. A number of websites give the necessary dietary intake for activities ranging from seditionary to very active. Unfortunately, as far as I can see, most do not envisage carrying a pack with gear for a week over mountains. Most calculators seem to provide for bursts of energy, not plodding along for 6-8 hours a day for a week or longer.

Is there a figure or range of dietary intake that is generally accepted for bushwalkers?

Secondly, there are too many units for this. Can someone please advise which unit is accepted in Australia? Is it calorie, Kcal, joule, BTU, Newton or something else?

Finally, what are the best food for a high energy/gram when bushwalking? TIA.

[Gadgetgeek]

yes, maybe, not really? Kcal is the metric unit, so its what is used in australia.

Personally, I prefer high protein foods for long endurance,I mostly go for nuts and that sort of thing. some prefer high complex carb.

There is a lot of differing opinion on what is best, and I suspect a lot of bad science and woo-doo floating around. I work on an N=1 sort of principal. If it works for me, thats what I go for. There are some pretty big flaws in measuring via calories, but there is also some major flaws in most of the "bio-availabilty" type stuff going around. It would seem from a lot of anecdotal evidence (and the plural of anecdote being not data) that it is possible that there is an upper limit to what the body can absorb, but the limit of output is much higher. Adding in to that differing metabolism, and metabolic changes over the course of the activity. As long as what you are eating is a good variety, and is of decent quality. you should be good. I eat lots of mixed nuts, cheese and to a lesser extent fruit and cured meat. I find that the greater variety I have, the better life is.
For straight up energy per gram, you'd be looking at something like macadamia nuts or something. But I don't know if that would be complete enough on its own to keep someone going for days at a time.

[LAMEA-Gals]

The best resource I have found is an American one by Brenda Braaten. She is a long distance walker as well as a dietitian. You need to go through her various papers but its worth the effort. She has numerous calorie calculations for your weight, your pack as well as break downs for protein, carbs and fats.

http://thru-hiker.com/articles/pack_light_eat_right.php

[neilmny]

My understanding is that calorie with a lowercase c is equal to kilo calorie (kcal). The use of the word calorie, if I understand correctly, is somewhat of an abbreviation of the term kilocalorie (kcal) to make it easier. Calorie with an uppercase C is 1000 calories or one kilocalorie.

[Lophophaps]

Thanks for the above posts, especially that of LAMEA-Gals. I have not had a chance to read Brenda’s very detailed advice, but it seems quite sound. Her background is very appropriate. I note with some amusement that she uses pound weight and grams. When will the US use metric? Also, Brenda uses Calorie, with an initial capital.

[Moondog55]

Energy density?
Fats and oils have the highest energy density.
Sugars metabolise fastest, starches digest more slowly and proteins release heat by way of complex processes as they are digested.
The US will go metric when hell becomes a lot cooler

[stry]

My understanding is that calorie with a lowercase c is equal to kilo calorie (kcal). The use of the word calorie, if I understand correctly, is somewhat of an abbreviation of the term kilocalorie (kcal) to make it easier. Calorie with an uppercase C is 1000 calories or one kilocalorie.

I think if I thought about that post Neil, it may very well explain why the Google converter for calories (C,c, whatever - I mean single calories to kilojoules is unintelligible.

Being old school, I tend to think in calories, which is not helpful when reading metric labels and building walking diets.

Not sure how any of that that helps me

[Orion]

yes, maybe, not really? Kcal is the metric unit, so its what is used in australia.

The calorie is metric but it's old metric. The modern unit of energy is the joule. Pretty much every food label I look at (outside of the US) gives the energy in kJ (kilojoules). But I haven't been to Queensland.

[Orion]

My understanding is that calorie with a lowercase c is equal to kilo calorie (kcal). The use of the word calorie, if I understand correctly, is somewhat of an abbreviation of the term kilocalorie (kcal) to make it easier. Calorie with an uppercase C is 1000 calories or one kilocalorie.

I think you have a typo in the first line as a calorie (lower case) can't possibly equal 1000 calories.

The large calorie, the Calorie, is equal to 1000 small calories (lower case). Which of course is also equal to a kilocalorie. I think the reason the Calorie was invented was because it's easier to say and write Calorie than kilocalorie. But it is confusing.

1 Calorie = 1000 calories = 1 kilocalorie = 4.18 kilojoules

[Orion]

Advice is sought on food. A number of websites give the necessary dietary intake for activities ranging from seditionary to very active. Unfortunately, as far as I can see, most do not envisage carrying a pack with gear for a week over mountains. Most calculators seem to provide for bursts of energy, not plodding along for 6-8 hours a day for a week or longer.

Google "Pandolf equation".

[icefest]

Google "Pandolf equation".

For the lazy people; this is the equation itself:

Code: Select all

W (J•s-1) = 1.5 M + 2.0 (M + L)(L/M)2 + n(M + L)[1.5V2 + 0.35VG]
M = body mass (kg), L = load carried, V = velocity (m•s-1), G = grade, and n is the terrain factor. For unloaded, level walking on a track or treadmill, the following formula is used: W (1 J•s-1) = 1.5 W + 1.5V2W

I'm not sure what the terrain factor for the WAs is though....

[Gadgetgeek]

Orion, you are correct. I get so lost with those units of measure that they don't stick into my brain in any sort of context. joules are the thing I was thinking of, maybe... or maybe I was flat out incorrect. Glad someone knows whats up.

[Mark F]

I don't know about others but my intake over the course of a walk varies quite significantly. On the first couple of days I usually eat very little - I have plenty of reserves. On these days I am eating only 4-5,000 kJ. This increases as the trip progresses but over week to 10 days I end up consuming about 9,000kJ per day. If find this translates to an average of 650-700 grams per day of food.

All the labels in my pantry show kJ not C or kc. Conversion 4.2 kJ to the C approximately.

[Orion]

I know people who basically don't eat the first day or two. I don't have a lot of reserves and wouldn't be happy for even a couple of days at the 5 MJ level you can get by on. For something around 10 days in length I find I need 13-15 MJ/day. Even this level is not sustainable (I lose weight) so for multi-week trips that are strenuous I need something around 20 MJ/day or else I eventually crash. On one month long bicycle tour where I maintained my weight I kept a food journal and found I was eating 20-25 MJ/day. After one long day on that tour I was so hungry I consumed a giant tin of butter cookies bringing the day's total to nearly 40 MJ.