1.25 lbs of food per day?

[James Pitts]

By the way, I got my package and, Sarah, thank you so very much for everything! Also, thank you for the recommendations. I love your cookbook, by the way, and bought it as soon as it was published. Keep up the great work!

[Sarah Kirkconnell]

Thank you, James! I figured you wouldn't refuse the freebies I slipped in ;-)

[D T]

The problem isn't that I need the calories, rather that my body quickly digests the small volumes of food (high in calories) and then leaves me feeling empty. I'm not actually starving, it's just a feeling of emptiness in my stomach. Part of the problem is that I drink lots of liquids and I'm guessing that it helps to wash the food too quickly through my system.

I have an active job and high metabolism, which means that I eat often. I do eat healthy and carbs are a regular part of my diet. The high daly carb intake of my diet may also be a contributing factor as to why I need bulk rather than calories in order to feel like I'm not starving.

As I stated in my previous posts, I'm going to change (at least for a weekend) my hiking pace. The slower pace might mean that my body won't metabolize the food so quickly. It also might reduce the amount of water I will need, which will help to keep the food in my stomach longer (just a theory). I'm also going to incorperate more whole grains in my menu in an effort to keep the "bulk" in my system longer.

In my case, this may not be a nutrition issue, but an issue of hiking technique. It also might just be a case of mind over matter (or lack of matter in my stomach). Trial and error, the trial is fun when it helps to reduce the weight of my pack.

James, if you find out what foods have a high "satiety response", I hope you will post them. This sounds very interesting to me.

[John S.]

Liquids do not wash the food through your system faster if you drink more. Feeling hungry soon after eating may be due to:

1. not enough calories
2. not enough protein or fiber in meal
3. pathological process

[mark henley]

Eins,

Nope, he's not into bodybuilding but he's certainly not a small fella, which brings up a great point buried in your post.

He's about 240 and about 6'2" ….. and a 10 mile day backpacking is a pretty good cardio session for him. Not completely out of shape but a good hiker. You've hit a good point here in that his body has to be starving for building material to regenerate. After all, our bodies are always trying to get back to homostasis. He's also been a more traditional backpacker carrying 40 to 50 lb loads. He's become a lightweight packpacker over the last year or so getting to a baseweight of around 12 to 13 lbs …. and that has certainly dropped his caloric needs as well as booosted his mileage.

[mark henley]

I'm posting a link to a caloric calculator from bodybuilding …. it should translate very well to any intense level of exercise such as backpacking.

http://www.global-fitness.com/BMR_calc.php

You can vary this number by 20% … 20% more, with adequate protein intake, will build muscle. 20% less, with adequate protein and nutrition, will result in fat loss with a little muscle loss.

As a side note: one gram of protein intake per pound of lean body mass would be key to not burning muscle on a long hike.

So … if you are of average fitness, burn an average of 450 calories per hour of intense exercise, and hike 10 hours a day, you'd need 4500 calories per day to maintain your current body mass. Drop that to below 3500 calories and your in starvation mode … which means being tired and lathargic all the time. Of course, your BMR plays a role in all of this as well.

3500 calories, divided by 120 calories per ounce of food yields 29 ounces of food per day (about 2 lbs).

In the short term you can fool your body into not kicking into starvation mode by using methods like the caloric drip method and maintaining an almost constant stream of nutrition during the day.

Whatever method you chose, however, you must realize that 20 ounces of food per day, times an average of 120 calories per ounce, yields 2400 calories. 2400 calories when your burning 4500 calories per day gives you a 2100 calorie per day deficit. One pound is 3500 calories, so this is more than half a pound of body mass loss per day.

On a long hike, not many people can stand 3.5 lbs per week of body mass loss … that's 15 to 20 lbs per month … and that's assuming that you have enough protein intake to keep your body from burning muscle … which burns easier than fat.

Of course … if your 160 lbs and 20 years old with 15% body fat, your body is much more forgiving of what you put into it. That changes with age.

Nutrition is huge, at least for us old dogs.

[mark henley]

Duane,

I've heard that Glen Van Peske hikes at an average of about 2 mph … he just hikes from 4am to 10 pm every day he's on the trail. Andy Skurka, however, hikes at 3.5 to 4 mph … covering 35 miles per day in the same time frame.

People are different … for example, I hike at an average of about 2.2 miles per hour on flat land, always have, and always will I imagine. Everyone has that one certain pace that when they hit the sweet spot … they feel as if they could walk "forever".

It is what it is … you can vary it with your level of fitness … but your limited by the biomechanics of your body somewhat …. stride length, etc.

There are a lot of guys that I hike with that have 36 or 37 inch inseams … and hike at an average of 3.5 miles per hour … so, we meet up at rest stops and in camp. For them to hike at my pace would drive them crazy … for me to hike at their pace would quickly wear me out.

Lastly …. I may be corrected by someone more knowlegable on the subject, which I would welcome, but I believe that caloric burn per hour is not nearly as dependent on hiking pace as it is on terrain. Fitday.com has some great caloric calculators for given exercises … their backpacking exercise model varies a lot with hours hiked, but not much with miles covered during that period. This would suggest that pace is a smaller variable in caloric burn than time spent in exercise.

Of course … runnning would burn more calories than walking for a given distance …. but running is a different exercise than walking even if they are similar.

[James Pitts]

For a given distance I don't think pace is as big of a contributing factor as the total mass of the hiker and changes in elevation (the route of the hike).

Consider the case of two hikers of the same weight hiking the same trail but one hiker moves twice as fast as the other. The faster hiker will certainly burn more calories per hour but they will also hike the trail in half the amount of time.

I am not saying pace is irrelevant, only that it's not one of the primary factors. Walking/hiking/running is a complex motion designed to return energy from the stride back to the body. A 60% return is the figure I have read. There are most certainly pace-dependant aspects at play here that are tied with that 40% that is not returned.

In running I have always used an estimate of .65 x body mass to get calories burned per mile. I have never had a way to gauge the accuracy of this.

[Erin McKittrick]

Makes sense…

With distance, terrain (elevation, brush, etc..), and pace being variable between people and between trips, I think that time really is the most sensible variable to look at.

It seems like most people walking pace themselves to have a relatively contstant energy output, more than a constant speed. Not completely, of course, but people go slower up hills and through brush, faster in open country, etc…

So hiker weight and time per day hiking should be the most important factors in calorie use. I think this is how most activity calorie calculators work.

So if the activities are significantly different than walking, it won't apply (climbing probably uses more calories per time, as does running, paddling uses less).

Erin
http://www.aktrekking.com

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