how many calories per pound per day do you eat?

I wrote: "Forcing myself to do that significantly lowered the energy density of my food, from about 2100 cal/lb to about 1800 cal/lb."
Tom wrote: "I would monitor this very carefully on longer trips, Ben. Depending on your amount of body fat, you could get away with this for awhile, but on longer trips I suspect you will find yourself in trouble."
I think you may have misread what I said. The 2100 and 1800 figures are calories per pound of food. Did you read them as calories per day?

We had this discussion about longer trips a few weeks ago. Since then I did a 12-day trip, which I described in the OP of this thread.

Quote "One thing that seems to be missing in the calories/lb calculations is that it does not account for body fat as a source of calories, unless I have missed something."
+1
my method what Ben called method 2 is better in my opinion.

On the last graph I think my point 22cal/lb is an outlier because of the long days we were putting in. Brian above me too, but to a greater extent.

It sounds like several people here are interested in seeing what the numbers look like when expressed as calories per total weight rather than just calories per unit body weight (what I referred to as method #2 earlier). If people are willing to supply the data, sure, let's go ahead and see the results. For me, the result is 13-16 cal/lb/day.

The question of whether people are burning fat is a good one. Actually there's more than one reason people would want to see data about this. If they simply want to avoid packing out a lot of food (which means carrying a lot of useless weight), then it's irrelevant to them whether or not a certain number of food calories is sufficient to supply the number of calories they're burning. On the other hand, if you're going on a long trip without resupply, you don't want to end up hungry because you're losing weight at a rate that would be acceptable (maybe even desirable) for someone doing a weekend hike.

I don't think we have any practical way of collecting data from BPL members that would be useful in accurately evaluating the fat factor. In most cases, fluctuations in weight due to the amount of food and water in your belly are likely to be big enough to mask any fat burned. Also, we don't know whether people are building muscle mass at the same time they're burning fat.

I did find some relevant information in Long-Distance Hiking: Lessons from the Appalachian Trail, by Roland Mueser. Mueser gives some data from his own surveys, and also passes on some numbers from a 1982 master's thesis by Karen Lutz, "Dietary Adequacy and Changes in the Nutritional Status of Appalachian Trail Through-Hikers." Lutz found that the AT though-hikers in her study ate an average of 4300 cal/day. There were five men and one woman in her sample. The men lost an average of 13 lb of fat and also lost 7 lb of lean body tissue. The woman lost 15 lb of fat and gained 5 lb of lean body tissue. The average starting body weight was 194 lb for the men, 142 for the woman. This gives an average body weight while hiking of 176 lb (assuming that weight loss happened at a steady rate).

In Mueser's group (a bigger, different sample), the average person had a pack weight of 40 lb, averaged about 15 miles on non-zero days, and completed the AT in 170 days.

Assuming body fat is 3500 cal/lb, muscle 600 cal/lb, the average energy deficit was 50,000 cal. Spread over 170 days, that's only about 300 cal/day. They burned an average of 4,600 cal/day.

So the amount of energy actually expended by people on the AT was about 26 cal per day per pound of body weight, or 21 cal/day per unit pack+body weight. The figures for what they actually ate would be 24 and 19. These figures are somewhat higher than what BPL members have mostly been reporting for the food they've actually been eating.

My executive summary so far would be that people generally need about 15-20 lb/cal/day on shorter hikes, more like 25 on long through-hikes.

"We had this discussion about longer trips a few weeks ago. Since then I did a 12-day trip, which I described in the OP of this thread."

True enough and, IIRC, you lost ~4.5#, which would indicate to me that you were not obtaining all of your calories from dietary sources. Let's assume for the purpose of this discussion that 3.5# of this was body fat/lean muscle, hopefully not much of the latter. That would = ~12,000 calories to be added to your total calorie consumption and then calories/pound of body weight calculations. I agree that it is difficult to determine how much fat has been lost, which is why it took me a couple of years to dial it in to the point where I could reliably depend on body fat as a source of calories and thus reduce the amount of food I have to carry. Anybody wanting to employ this strategy will probably also have to go through a period of trial and error. It's an interesting exercise with the potential to save multiple pounds of food, depending on trip length. In a communtiy of gram counters this is a huge, and often overlooked, payoff, IMO.

Tom wrote: "I would monitor this very carefully on longer trips, Ben. Depending on your amount of body fat, you could get away with this for awhile, but on longer trips I suspect you will find yourself in trouble."

I wrote: "We had this discussion about longer trips a few weeks ago. Since then I did a 12-day trip, which I described in the OP of this thread."

Tom wrote: "True enough and, IIRC, you lost ~4.5#, which would indicate to me that you were not obtaining all of your calories from dietary sources. […] That would = ~12,000 calories to be added to your total calorie consumption and then calories/pound of body weight calculations."

Hmm…one of the reasons I don't like web forums as well as usenet is that most web forum software makes it extremely difficult to have any kind of organized, logical discussion of a subthread like this. I can't even figure out a good way on BPL to refer to a specific post within a thread, other than by giving the date and time.

For the reasons given in my post on 08/02/2010 17:48:19, page 1, I don't think the 4.5 lb figure for my weight loss has enough precision to mean anything. In any case, a sample size of 10 is small enough. Focusing on one data point — me — out of the 10 is really not a good idea.

Your first quote above says you think I will find myself "in trouble." The point of my quote above is that I did not find myself in trouble. The hike went fine. I was always satiated, felt great, had plenty of energy, and exited with a huge amount of uneaten food.

For the reasons given in my post on 08/06/2010 12:39:06, page 3, I don't think any of the data collected from BPL members tell us anything useful about calories expended, only about calories eaten. That's why I analyzed the figures from the AT through-hikers, which do tell us about calories expended.

Ben wrote:For the reasons given in my post on 08/06/2010 12:39:06, page 3, I don't think any of the data collected from BPL members tell us anything useful about calories expended, only about calories eaten. That's why I analyzed the figures from the AT through-hikers, which do tell us about calories expended.
If you can't accept input from BPL members as meaning anything. then it would probably be good to include people who have also hiked the CDT and the PCT instead of concentrating on just the AT, seems it would give you a better representation of long distance hikers IMHO.

"Hmm…one of the reasons I don't like web forums as well as usenet is that most web forum software makes it extremely difficult to have any kind of organized, logical discussion of a subthread like this. I can't even figure out a good way on BPL to refer to a specific post within a thread, other than by giving the date and time."

Yeah, wouldn't it be nice if we could all sit around a table with some beers and bat this back and forth? But it is what it is.

"For the reasons given in my post on 08/02/2010 17:48:19, page 1, I don't think the 4.5 lb figure for my weight loss has enough precision to mean anything. In any case, a sample size of 10 is small enough. Focusing on one data point — me — out of the 10 is really not a good idea."

If your controls were that loose, why in the world did you even bother to mention it? I agree, it would not be a valid data point if you were dressed in street clothes and just back from a prime rib dinner and a couple pints of beer. However, you are not the only data point in this thread. Derek Goffin, Greg Gressel, John Vance David Lutz and Brian Senez, have all weighed in on the subject, a couple of them with some degree of precision. It also tracks with my own experience, which I have gone into in considerable detail in threads past.

"Your first quote above says you think I will find myself "in trouble." The point of my quote above is that I did not find myself in trouble. The hike went fine. I was always satiated, felt great, had plenty of energy, and exited with a huge amount of uneaten food."

I edited my original post to reflect the fact that I misread your original statement and deleted the comment upon which it was based. I will restate here. Yup, I misread it and withdraw my comment. I will add that the reason you felt so strong may have had something to do with that 4.5 pounds or whatever that you lost. You had to get the calories somewhere.

"For the reasons given in my post on 08/06/2010 12:39:06, page 3, I don't think any of the data collected from BPL members tell us anything useful about calories expended, only about calories eaten. That's why I analyzed the figures from the AT through-hikers, which do tell us about calories expended."

Maybe a more well designed questionnaire would get the ball rolling. In its absence the folks I mentioned above did their best to fill in the blanks. Many of the folks here on BPL are highly experienced and definitely have worthwhile data to contribute if the questions are put to them in an organized and comprehensive fashion.

I would recommend that, in your spare time, you browse through past threads on this subject(there are several) and take a look at the Arctic1000 website writeup on food, as well as Kevin Sawchuck's post on food in his Parcour de Wild trip report. Body fat figures heavily in all of the above sources. It's not a hypothesis, but has been very thoroughly studied by exercise physiologists. Specific measurements for a subset of the BPL community, AT through hikers, or whatever group you choose may be an interesting project, but I doubt very much if you will end up shedding new light on the subject. In the end each person is going to have to adapt the technique to their particular style of backpacking, if they so choose, and refine it through trial and error. We're each unique, but our bodies all operate according to the same basic principles.

Unfortunately the Hammer Nutrition website has alot of crap for information that is wrong. It's there to deceive you into buying their products. Some of the products would be good for competitive sports where you cannot stop to eat, but none of it is needed for typical backpacking. The below quote is one misinformation packet they are selling you,

"Sugar Bad – Avoid all "ose" (sucrose, fructose, glucose, etc.) highly processed sugars in your daily diet and especially during exercise. These sugars are not only inefficient fuels, they're health hazards as well."

"Unfortunately the Hammer Nutrition website has alot of crap for information that is wrong."

While I would agree that Hammer and most other supplement websites skew the information to their benefit I'm not sure they are wrong. You have to remember who they are marketing and designing their products for. It not the 12 mile per day weekend backpacker; it is ultra-marathoners and similiar "extreme" athletes. In that context I'm not convinced that they are far off the mark.

May have drifted from original questions, "how to hike on a non-cook" or "liquid" fuels.

If the hiker is trying to do:

– fast-paced, high mile days
– Get on trail with low time-waste , low prep, less stopping
– Low fuel/food pack weight

Then liquid/powder fuels (Gu, CytoMax, Accelerade, etc.) is a good option. Comparing ultra, low-weight, fueling with a more relaxed hiking style is not a proper comparison.