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 Tom Kirchner (ouzel) - MLife Locale: Pacific Northwest/Sierra optimizing backpacking menu on 11/05/2006 18:12:55 MST I am in the process of trying to optimize my backpacking diet for the Nth time and am interested in any and all comments, advice, etc.Assumptions1) I weigh ~137# and usually add ~5# of body fat gradually over the month before long trips (10-12 days in my case).2) Pack weighs ~ 30# and clothing worn 3.5# for total weight of 175.5# (the weight I use to calculate calorie expenditure).3) I use a calorie expenditure calculator with backpacking as the activity and a weight of 175 to get a calorie estimate of ~ 4450.4) My food yields ~2925 calories/day with 1440 cal from carbs, 308 cal from protein, and 1177 cal from fat.This leaves me with a calorie deficit of~1525 calories to derive from body fat,which equals ~ .44# of body fat, sufficient to make up the deficit for 11 day plus a little. This diet tries to replace most of my glycogen on a daily basis, provide enough protein for body repair with a little in reserve for gluconeogenisis if I exhaust my glycogen, and provide as many calories as I can from dietary fat with the remaining weight. I would greatly appreciate feedback.
 Richard Nisley (richard295) - M Locale: San Francisco Bay Area Re: optimizing backpacking menu on 11/05/2006 21:53:14 MST Tom-A unit of metabolic equivalent, or MET, is defined as the number of calories consumed per minute in an activity relative to the basal metabolic rate (BMR). A single unit (1 MET) is the caloric consumption of that individual, while at complete rest, aka BMR. For example the restful state following a quiet night's sleep is a single MET. Hiking cross country, or backpacking, averages 6 MET with an adequate diet. Burning fat, carbohydrates and proteins is referred to as substrate utilization. Your planned substrate utilization is 32% CHO, 61% fat, and 7% Pro. For any 6 MET sport, which lasted about an hour or less, your actual substrate ratio utilization would be ~ 39% CHO, 56% fat, and 5% pro. After about 3 hours at 6 METs, your substrate utilization should have shifted to burn at least 10% more fat. Your planned substrate utilization looks fine.I used the mean values for endurance athletes in the above brief analysis. They have a rough bell curve distribution of substrate utilization ratios. It starts with rest and persists during exercise of increasing intensity. The major determinants of resting "respiratory equivalence ratio" (RER) are: muscle glycogen content, training volume, proportion of type 1 fibers (slow twitch), FFA / lactate in your blood, and % dietary fat intake. This is a long winded way of saying, "Only taking an RER test will result in 100% accuracy for your planned substrate utilization." Edited by richard295 on 11/06/2006 23:39:16 MST.
 Sam Haraldson (sharalds) - MLife Locale: Gallatin Range optimizing backpacking menu on 11/06/2006 10:51:57 MST Richard - When referring to CHO do you mean carbohydrates? Edited by sharalds on 11/06/2006 14:21:47 MST.
 Richard Nisley (richard295) - M Locale: San Francisco Bay Area Re: optimizing backpacking menu on 11/06/2006 11:11:32 MST Sam-Yes
 Tom Kirchner (ouzel) - MLife Locale: Pacific Northwest/Sierra Re: Re: optimizing backpacking menu on 11/06/2006 18:43:24 MST Hi Richard,Many thanks for the really informative beta. You have pushed me further along a path I was just starting out on. For years I have pretty much adhered to the approach taken by Ryan, Roman, and Jason for the Arctic 1000 trek and it served me decently for the longer trips of my younger days-in the 16-17 day range. But I was carrying much heavier loads then and calories, not speed, was the issue. More recently, as I moved in the direction of lightweight, if not ultra light, backpacking, I began to up the percentage of CHO in my diet, but was never sure how far to take it because as CHO increases, either calories decrease or weight increases with all that implies in terms of limitations on trip duration, pack weight, etc. So, it was pretty much trial and error. You have given me a much clearer idea of the tradeoffs involved in terms of CHO percentage and pace which will come in especially handy for some PCT section hikes I am contemplating, where a faster pace is required if one is to cover the distances involved in a practical timeframe. Heretofore the type of backpacking I have done-mostly off trail wandering-rarely put me much above the 4 MET range except for booking on out the last day or two. Never had much trouble making it back to the car, BTW. Guess it was that pot of beer I visualized at the end of the rainbow:-)...
 Richard Nisley (richard295) - M Locale: San Francisco Bay Area Re: optimizing backpacking menu on 11/06/2006 23:41:28 MST Tom-I recalcuated the numbers and discovered I screwed up on my original post yesterday. I went back today and corrected the original post numbers. I shouldn't have checked my numbers before I posted them the first time... sorry.
 paul johnson (pj) - F Locale: LazyBoy in my Den - miss the forest Re: optimizing backpacking menu on 11/07/2006 02:13:11 MST Sam, Richard already answered you. I'm only adding, IIRC basic biochem (i don't trust my memory any longer; some of the simplest things i forget), CHO is used since carbs (whether simple sugars or starches) are composed of only three elements C[arbon]-H[ydrogen]-O[xygen] in varying combinations and arrangements, hence CHO. Just thought someone might like to know. Furthermore, amino acids add in nitrogen, and some also have sulfur (and we all know what happens if many of the sulfurous AA's are consumed). This is why, in some fields (e.g. Microbiology) carbs are spoken of as a carbon source, and AA's as a nitrogen source (just two of several basic requirements for culturing nearly all bacteria). Someone might, from time to time, also hear the terms "carbon source" and "nitrogen source" - hence, my explanation of those terms also. Edited by pj on 11/07/2006 02:38:53 MST.
 Tom Kirchner (ouzel) - MLife Locale: Pacific Northwest/Sierra Re: Re: optimizing backpacking menu on 11/07/2006 18:15:15 MST Hi Richard,Thanks for being so conscientious. I really appreciate all this feedback. While we're on the subject, could you tell me how the ratio would shift if I were to drop back to a 4 MET level of output(~2.5 mph), which is the level I would probably shoot for if I were trying to extend my trip out to,say, 18 days, i.e. the kind of trip where I just wanted to get out there and wander around without any "balls to the wall" agenda? My sense is that I would up the fat percentage a la Arctic 1000, but it would be nice to hear your perspective on the subject.
 Tom Kirchner (ouzel) - MLife Locale: Pacific Northwest/Sierra Re: Re: Re: optimizing backpacking menu on 11/07/2006 18:17:33 MST Another point. If I'm on the right track, would I also want to pack another 2.5-3# of lard around my middle?i.e. ~.44# per day x 6 additional days?