I've heard that for people who don't live at altitude the adjustment period can increase your BMR anywhere from 6-24% (yeah, kind of a huge range), do you guys pack for that accordingly? I mean, I pig out anyway, but I'm not sure I want to carry more food unless I have to.

I lose appetite at high altitudes (10,000 feet and above), so I pack less food for the first 4 or 5 days. Of course I can always afford to lose some weight!

I don't know if pigging out before the trip so you have a few extra pounds to lose is a good idea or not.

I agree with less food is eaten at High altitude, at least my appetite is suppressed at Higher Altitude or so it seems.

I've also experienced a loss of appetite at the beginning of trip at altitude. It seems that about the 3rd or 4th day I start sucking calories at a more normal rate. I just wish I felt secure enough to pack accordingly. I've gotten better at it with experience but still occasionally over-pack and eat more than I really want too at the beginning. At about day 12 all bets are off and if there is food I'll eat it.
At around day 20 on the trail the food fantasy's strike if I haven't had a resupply in town. My most creative one was a desire for an extra large pepperoni pizza wrapped around 2 cheeseburgers. I'm glad I didn't act on the impulse when I did get into town.

Yeah, that reflex is definitely common. Appetite suppression is, I think, associated with hypoxia. But at least initially, your BMR increases. So your body is hungrier, despite you not feeling it. You're actually in pretty serious calorie deficit.

https://wms.org/news/altitude.asp


Abrupt exposure to elevations greater than 10,000 ft (3,050 m) is frequently associated with symptoms of altitude illness. Altitude illness is a combination of symptoms, including headaches, anorexia, nausea, vomiting, and malaise. The combined effect of these symptoms is usually a profound depression of appetite and reduction of food intake, just at the time when the climber needs energy the most. Climbers that anticipate the consequences of altitude-impaired appetite may at least minimize the secondary consequences of the cachexia of altitude: reduced energy intake, depleted muscle glycogen stores, negative nitrogen balances, and loss of critical lean body mass.

Gradual acclimatization to progressively higher altitude exposure is the best preventive medicine for high-altitude sickness. Unfortunately, it is not always practical or possible to delay ascent to altitude. Rescue workers frequently must travel abruptly to high altitudes to perform critical tasks. Prior acclimatization is not always possible. Abrupt transportation from sea level to high altitude may be accompanied by debilitating altitude sickness symptoms, including altered mood, appetite, and performance. These uncomfortable symptoms usually increase in intensity for periods of up to 48 hours after altitude exposure and then gradually lessen. Unfortunately, it is usually during the first 48 hours at altitude that critical work must be accomplished. The strenuous activities associated with work or recreation at altitude, plus an initial increase in resting metabolic rate and the lack of adequate food intakes almost invariably result in an initially negative energy balance. Altitude illness can limit volitional activity, but energy expenditures of experienced and motivated climbers who are acclimatized can be quite high, depending upon the activity level achievable under hypoxic conditions.

Edited by tekhna on 05/28/2012 23:43:29 MDT.

Don, I think you're doing the right thing in eating more than you want to at the beginning.

I agree. There is generally a small decrease in appetite for the first few days, but your work output may be high. As a result, you may lose weight in those first few days. That finally stimulates increased appetite to maintain weight, but not to gain back what you first lost.

When you go above 16,000-18,000 feet, not only does your appetite amount change, but also the types of food.

--B.G.--

I wholeheartedly agree with Bob above. When you hear "I lose a lot of my appetite at high elevation" people mean for a few days. If you go on a weekend trip at 12k, you'll eat less. If you go on a 2 week trip, you'll eat less for 2-4 days, then eat ravenously.

I plan on 2500 kcals for the first 2 days (I'm 6'3" 220) that I plan to force feed myself because I won't be hungry enough, then 3000 every day after that. I think last year on the JMT I planned for 1.8 lb of 125-150 kcal/ounce food, had leftovers at first, then ran out of food maybe a day early (I was going very quickly, so luckily that worked out). It's really hard to guess these things, but a lot of longer trips (no offense to you triple crowners) like the JMT you'll find food bins at resupply points with extra in them free for the taking, so that'll help you either as a waste-collector or as a "free food, yeah!".

Edited by Trout on 05/30/2012 16:02:49 MDT.

I'm definitely in the minority. My appetite never really decreases at altitudes in the lower 48. Maybe if I kept a sea level food log vs 11,000' food log there would be a difference. But I can guarantee you that when I get to my camp @ 11,000' I'll be eating all the hot food I can find.

If you go back in history to 1953, John Hunt was leading the British expedition attempting to climb Mount Everest. Since Hunt was a former military man, he had the expedition food planned out like a military campaign. His climbers kept moving their camps higher and higher, and the cooks tried to keep up. After they got far above 22,000 feet or so, the appetites began to wane amongst most of the climbers. Enough of that, and their energy levels began to wane as well. The exception was the young New Zealand beekeeper by the name of Ed Hillary. When the other climbers lost their appetites and could not eat their shares, Ed cleaned up. He managed to keep his appetite going full-throttle, so he managed to keep his energy level high. Then, some days later, he and Tenzing were standing on the summit.

I think part of the moral of the story is that you might need to force yourself to eat, even if your appetite is lacking. It helps if you have some food that is so dearly your favorite that you can eat it under any conditions.

--B.G.--

I made it a point NOT to pig out before a trip, because I know I will feel sluggish and tired at the beginning of a trip, when I'm also carrying the heaviest load at the start.

+1 on the appetite loss over 10,000' elevation, or even on a multi-day at moderate elevation. Everyone is different, but my experience is that my appetite and taste buds completely reject repetitive and packaged foods (Cliff Bars, etc)

So for me, I have to diversify the menu to make it interesting, otherwise my comfort is to skip meals on the trails. I have to force myself to finish my food allocation.

After every trip, I keep a lessons learned list, and a list of what-worked, and what failed. For me - small bites of a big variety works best, as opposed a big meal of one variety. pretzels, smoked salmon, jerky, tuna and chicken in foil pouch, mixed bagels, single servings of fruit jams and jelly, single servings nutella I love you, pre-cooked rice with bacon and ground beef vacuum sealed, gummy vitamins, licorice candy, Altoid mints, olive oil and zaatar thyme oregano pesto on bread, hard boiled eggs, spam singles. I also go for pringles, and pre-popped popcorn that I stash in a no-crush disposable container such as the large Lysol wet-wipe tube containers.

On my first BP trips, I packed 3-4 lbs of food per day, obviously too much, now I aim for 1 lb per day to eat, plus 15% extra calories per day for emergency, but no more than 1 solid extra day of emergency food per trip.

The emergency food usually get allocated to BP trip buddies who reject the food they packed and start craving "what the other guy is having"

Edited by RogerDodger on 05/31/2012 15:51:35 MDT.

It really depends on the Time you are there.

I did cross the Thorong-La with 5416 with the Yak-Attack Bike-Race.

We were "only" a few days ofer 3000m and I really couldn't get enough food. Soo I took some Energy Gel's and they worked before I got into the hypoglycaemia.

Biggest problem was more the freezing of the camelbaks. So Try to get enough to drink because Hiking the half day without getting anything to drink is REALLY not helping.

greetings
Thomas

I have found that carbs work better than fats and proteins at realy high altitudes, say 5000 meters plus. Metabolizing food requires oxygen, and fats and proteins require more of it for their metabolization. Glucose, the basic unit of carbohydrate contains half of the oxygen required for its metabolism in embedded in the molecule. Things like mashed potatoes, instant rice, and sports drinks go down really easy and provide a lot of quick energy. This is not to say don't use any fat or protein but, rather, shift the emphasis to carbs. I think it also helps to go in with a few extra pounds of body fat that can be utilized on demand without requiring digestion, if you can supply the carbs to feed the Krebs Cycle. I also think the same principle applies when you are ascending to altitudes over, say, 10,000' relatively rapidly. My 2 cents.

>> "it also helps to go in with a few extra pounds of body fat"

I'm already there :)

My experience...... I can't. But I have been able to drink at elevation. Building on toms comments, if I were going from low to high elevation such as the Sierra, I would still target my full daily calories but I change the composition. I would lean heavier on my maltodextrin mix because I know I can drink it even when I wont eat the yummiest of foods. One other point, try not to restrict your calories due to loss of appetite. You likely will need the calories more at higher elevations than at lower. I learned this the hard way on the Sierra High Route.