View Full Version : Calories per day formula
A friend of mine who knows a lot about nutrition shared this with me. It seems like it's pretty accurate, since it gave me around 4150, which seems about right for my height and weight. Anyways, I thought I'd post this for you all:
[655 + (6.2 x Weight in pounds) + (12.7 x Height in inches)] - (6.8 x Age in years) = total calories per day
Jonnycat
06-13-2011, 21:27
It depends a lot on your level of activity throughout the day, which yields a modifier based on the Harris-Benedict equation.
More here: http://www.bmi-calculator.net/bmr-calculator/harris-benedict-equation/
It depends a lot on your level of activity throughout the day, which yields a modifier based on the Harris-Benedict equation.
More here: http://www.bmi-calculator.net/bmr-calculator/harris-benedict-equation/
And, according to the BMR formulas posted on the above site, that first constant should be 66 vice 655 for males. The BMR formula for females is:
655 + ( 4.35 x weight in pounds ) + ( 4.7 x height in inches ) - ( 4.7 x age in years )
SassyWindsor
06-13-2011, 23:50
If one is aggressively distance hiking then eat all the calories you can, you'll still, most likely, loose weight
If one is aggressively distance hiking then eat all the calories you can, you'll still, most likely, loose weight
For a thru hiker it doesn't need to get any more complicated than that.
For a thru hiker it doesn't need to get any more complicated than that.
I wonder. For the younguns that's probably true. But these formulas suggest that for me - a 6', 190 lb, 56yo, I'd be burning ~3388 calories. A goodly distance from the oft quoted 4K! A 22 yo of the same gender, height and weight is closer to that 4K figure at 3828 calories.
4150 seems low to me but I just let my gut figure out the math. Amazing how that works.
sixhusbands
06-14-2011, 12:11
I am 5'8", 180 , 60 year old and I come up with 2227 as my calorie for the day. This is fairly accurate for me in a normal day. What factor is used for increased activity such as hiking for 8 hours day? I see the high counts and i am curious as to how they reached them
As a woman, I can only state that I managed to lose over 10 percent of my body weight by the time I saw my first scale (Hot Springs) while eating way more than twice what the formula calls for (when using the high value, not the lower body weight value). There simply no way to backpack in tough conditions on less than 1500 calories per day without losing weight.
This might work for a sedentary lifestyle, have no muscles, and stay in a heat-controlled environment all day, but there's no way it's accurate if your fighting cold weather and carrying a pack all day.
I assume you add full pack weight (incl water) to the weight part of that formula, correct?
Lexi1987
06-14-2011, 13:25
It estimated 2,142.8 for me. Uh, what, for dinner? Lol. :O
Yeah, that formula can't possibly take into account hiking rugged terrain plus it seems to be missing a component for hours or minutes of hiking. For the guy or gal that hikes 10 or 12 hours a day the calories burned will be much greater than for 6-8 hour hiker.
A friend of mine who knows a lot about nutrition shared this with me. It seems like it's pretty accurate, since it gave me around 4150, which seems about right for my height and weight. Anyways, I thought I'd post this for you all:
[655 + (6.2 x Weight in pounds) + (12.7 x Height in inches)] - (6.8 x Age in years) = total calories per day
Hate to point this out but to end up with 4150 calories based upon this formula, assuming you weigh 200lbs and noting your age as 19 years old, you would need to be 187 inches tall or...15.6 feet tall. Maybe you are six feet tall and weigh 437lbs?
I'm 6'6" and weigh 230 at age 37 and end up with 2820 calories which doesnt even come close to my needs on an active day.
DWAYNEEDWARDMOORE1@r
06-14-2011, 14:40
you will always be hungry on a thru/hike.Easy method carry food thats lite but high in calories carb.& protein.When you get to town load up on calories.
The way I understand it, the basic formula determines one's "Basal Metabolic Rate (BMR)" which is the number of calories you'd burn if you stayed in bed all day. These formulas are different for men and women. The site cited by Johnnycat lists these as the formulas for BMR:
Men - BMR = 66 + ( 6.23 x weight in pounds ) + ( 12.7 x height in inches ) - ( 6.8 x age in years)
Women - BMR = 655 + ( 4.35 x weight in pounds ) + ( 4.7 x height in inches ) - ( 4.7 x age in years)
I am 5'8", 180 , 60 year old and I come up with 2227 as my calorie for the day. This is fairly accurate for me in a normal day. What factor is used for increased activity such as hiking for 8 hours day? I see the high counts and i am curious as to how they reached them
It depends a lot on your level of activity throughout the day, which yields a modifier based on the Harris-Benedict equation.
More here: http://www.bmi-calculator.net/bmr-ca...dict-equation/
As Johnnycat pointed out above, you figure your BMR then multiply it by a factor based on level of activity - The site listed these:
If you are sedentary (little or no exercise) : Calorie-Calculation = BMR x 1.2
If you are lightly active (light exercise/sports 1-3 days/week) : Calorie-Calculation = BMR x 1.375
If you are moderatetely active (moderate exercise/sports 3-5 days/week) : Calorie-Calculation = BMR x 1.55
If you are very active (hard exercise/sports 6-7 days a week) : Calorie-Calculation = BMR x 1.725
If you are extra active (very hard exercise/sports & physical job or 2x training) : Calorie-Calculation = BMR x 1.9
Yeah, that formula can't possibly take into account hiking rugged terrain plus it seems to be missing a component for hours or minutes of hiking. For the guy or gal that hikes 10 or 12 hours a day the calories burned will be much greater than for 6-8 hour hiker.
Great point. Is a 12 hr a day hiker a 1.9? A 3?
I assume you add full pack weight (incl water) to the weight part of that formula, correct?
Good question. I'd think so. It'd make a strong argument for going ultralight :D
Jonnycat
06-14-2011, 16:17
Great point. Is a 12 hr a day hiker a 1.9? A 3?
Darn good question. There are websites which give "calories burned per hour" ratings; one site (http://www.sparkpeople.com/resource/calories_burned.asp) gives a rating of a little less than 600 calories per hour for a person of my weight, hiking (climbing hills) with an UL load.
Fortunately, most hiking isn't all climbing hills, so maybe the average would be somewhat less than that.
I caution you to not live life, plan you trailfood needs, and hikes according to an equation. Use the equation as a general base line and work from there. YOU should be flexible in your approaches and aware of your needs. This equation is only a tool that probably leads to some ballpark caloric recommendations. NO caloric equation can determine exactly how many cals you will need because too many variables come into play concerning your individual caloric needs that the equation does not recogonize!
Darn good question. There are websites which give "calories burned per hour" ratings; one site (http://www.sparkpeople.com/resource/calories_burned.asp) gives a rating of a little less than 600 calories per hour for a person of my weight, hiking (climbing hills) with an UL load.
Fortunately, most hiking isn't all climbing hills, so maybe the average would be somewhat less than that.
That link won't work like that. This one should:
http://www.sparkpeople.com/resource/calories_burned.asp?exercise=11
It says I burn nearly 800 calories per hour. That sounds about right based on my daily intake and weight lost last year. Even though I was eating 4500 calories a day on the trail, I still lost a pound a day for every day I was on the trail. And it requires a calorie deficit of ~3500 calories to lose a pound.
That link won't work like that. This one should:
http://www.sparkpeople.com/resource/calories_burned.asp?exercise=11
Interesting that it doesn't take age or gender into account ...
Jonnycat
06-15-2011, 09:01
Interesting that it doesn't take age or gender into account ...
My guess would be that during an activity, it is only the physics of the activity that matter, which would only be concerned with a person's weight. An analogy could be made to how much force it takes to move a lever, regardless of the composition of the lever, that sort of thing.
A BMR, in contrast, does depend upon age, as younger people tend to have a higher resting metabolism than those with more experience under their belts.
I would still think it would include height, though.
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Back to your original question, as to what the modifier would be for a person hiking 12 hours a day, if we assumed that (for me), an hour of hiking burned 550 calories, a 12 hour day would burn 6600 additional calories.
Given that my BMR is 1772, and a base state Harris-Benedict modifier of 1.2 gives 2126 calories per day to maintain my weight, my total for day of hiking 12 hours at 550 calories per hour would be 8726, which would yield a Harris-Benedict modifier of about 4 if my math is correct.
I can hike a long day also, but I definitely slow down after a few hours. If I stop and rest and have a snack I can pick up the pace again. I am not sure I could maintain 550 per hour for 12 hours unless I was highly motivated, and then I don't think I could maintain it over multiple days. Plus there is the tree factor, which I recently discovered, which is that you are more likely to trip and bump your head on a tree or rock as the days and hours progress.
8726 calories per day seems very high to me unless you are really hauling ass.
So I think some might use a 4 modifier, but most maybe 3, or even 2. So it depends. My last hike I was carrying 20 pounds skin out on my 220 pound body, and averaged 12-15 mile days over 8-12 hours with moderate terrain, and burned 0.5 pounds of food per day plus about 1 pound of body fat, so about 4400 calories per day, compared to my basal metabolism of 2000 or 2200, so a modifier for me of about 2.0 to 2.2 .
With more severe terrain, like the Fundy Footpath with lots of ups and downs, I the modifier would be closer to 3.0 for a 8-12 hour day. So 2.0 to 3.0, for me.
My guess would be that during an activity, it is only the physics of the activity that matter, which would only be concerned with a person's weight. An analogy could be made to how much force it takes to move a lever, regardless of the composition of the lever, that sort of thing.
A BMR, in contrast, does depend upon age, as younger people tend to have a higher resting metabolism than those with more experience under their belts.
I would still think it would include height, though.
Back to your original question, as to what the modifier would be for a person hiking 12 hours a day, if we assumed that (for me), an hour of hiking burned 550 calories, a 12 hour day would burn 6600 additional calories.
Given that my BMR is 1772, and a base state Harris-Benedict modifier of 1.2 gives 2126 calories per day to maintain my weight, my total for day of hiking 12 hours at 550 calories per hour would be 8726, which would yield a Harris-Benedict modifier of about 4 if my math is correct.
I found this in Conditioning for Outdoor Fitness in Google books:
http://books.google.com/books?id=ctmx9xS0WH4C&pg=PA29&dq=harris-benedict+backpacking&hl=en&ei=Jbb4TdeuIMja0QHohtSaCw&sa=X&oi=book_result&ct=result&resnum=4&ved=0CDsQ6AEwAw#v=onepage
They use a similar formula to determine what they call a resting metabolic rate. Then later say (paraphrasing):
A 40 yo, 5'9", 166 lb male has an RMR=1671. With a 44 lb pack, hiking 8hrs/day in the mountains, w/2 hrs of breaks, he adds a caloric requirement of 600 kcals/hr, times 6 hrs, for 3600 additional calories over RMR, or a total of 5271/day
I plugged that into my spreadsheet I came up with a factor of 2.7 - for an eight hour day with six hours of walking ... A ten hour day would be a bigger factor based on the above info ...
So, to get to your point, instead of using the multipliers, one might add "Hours Hiking" times 600 k/cal to the BMR (hrs * 600 + BMR) for an estimate.
Here's the spreadsheet (https://spreadsheets.google.com/spreadsheet/ccc?key=0ApOKl2Ya2LXmdGthUG5MbjZodTViU1dtRVZFNFE0Z 3c&hl=en_US&authkey=CLzOzPUH) I've been playing with. Still trying to figure out best way to separate pack weight from BMR
Cheers
Jonnycat
06-15-2011, 16:00
So, to get to your point, instead of using the multipliers, one might add "Hours Hiking" times 600 k/cal to the BMR (hrs * 600 + BMR) for an estimate.
I like your method, Willy, it makes even more sense. It would also allow a modification of the calories burned per hour, depending, as JAK brought up, upon one's level of exertion during the time spend actively hiking.
chasegru
06-15-2011, 18:44
So, to get to your point, instead of using the multipliers, one might add "Hours Hiking" times 600 k/cal to the BMR (hrs * 600 + BMR) for an estimate.
Here's the spreadsheet (https://spreadsheets.google.com/spreadsheet/ccc?key=0ApOKl2Ya2LXmdGthUG5MbjZodTViU1dtRVZFNFE0Z 3c&hl=en_US&authkey=CLzOzPUH) I've been playing with. Still trying to figure out best way to separate pack weight from BMR
I prefer to use miles hiked and elevation gained and add that to BMR:http://www.thruhikercaloriecounter.com/uploads/6/0/2/9/6029364/3848654.jpg?408
Far as seperating pack weight from BMR...there's an app for that (http://www.thruhikercaloriecounter.com/appalachian-trail-calories.html)...
SassyWindsor
06-15-2011, 21:01
I never worry about calories while on a hike. It's when I STOP hiking that calorie management becomes a headache. I have never, NEVER, come off a hike and had a weight gain and I can't remember any of my hiking friends complaining about gaining weight during a hike.
I only worl calories during a hiking because I am trying to use them to maximize weight loss, without bumping into trees and falling off cliffs. If I was thinner I would worry less.
Sorry for all the posts. On my last hike I think I was successful in determining that I can get away with as little as 0.5 pounds per day, and still hike a full day, but I am not sure yet that it will work on the Fundy Footpath where I know I can burn more calories per day because of all the uphills and downhills, but it does take more carbs, not just more body fat. I think I confirmed for myself I can only burn about 1 pound of fat per day while hiking. As I thin out it will be less than that, but for now I have about 65-70 pounds of body fat. I think 1% of your body fat per day is a good rule of thumb, but while hiking you can burn more on long slow days. I might use 2% of my EXCESS body fat as my rule of thumb. I figure I have 50 pounds of excess, so 1 pound per day if I hike 10 hours or more. If I get down to say, 10 pounds excess, I will only count on 0.2 pounds per day from my fat stores, and will add some fat to my diet. For now my hiking diet is mostly carbs and protien, even though I burn mostly fat.
SassyWindsor
06-15-2011, 21:19
I've met a couple of hikers who were hiking to lose weight. The biggest problem they were having was not eating enough to keep up strength and they were also getting dehydrated easily. I also sensed they were not really enjoying their hike, but this could have been due to some underlying health problems.
aaronthebugbuffet
06-15-2011, 21:58
Here's an interesting read about 3 formulas for calorie calculation and macro nutrient ratios.
http://forum.bodybuilding.com/showthread.php?t=121703981
Eat healthy foods and let your body tell you what to do. If you consistently have odd cravings you're probably missing something important.
there's just so many factors that come into play
age, weight, height, etc.
temperature
miles hiked
elevation gain
terrain
pack weight
shoe weight
stride efficiency
fat stores used
etc.
Far as seperating pack weight from BMR...there's an app for that (http://www.thruhikercaloriecounter.com/appalachian-trail-calories.html)...
Is that an iPhone app? I couldn't tell from the web site.
chasegru
06-25-2011, 13:50
Is that an iPhone app? I couldn't tell from the web site.
It an old school PC app--getting an iPhone app developer proved a bit too difficult.