Energy availability and sufficient intake
oat_bran
Posts: 370 Member
Does anybody know how calculating energy availability works?
For the context, I am trying to go back to losing weight again and I'm trying to calculate the right intake. The thing is I prefer to use the "TDEE - deficit" method instead of "eating the exercise calories back" because logging exercise would be just too complicated for me. Some days I don't do any "actual exercise" but my job or chores keep me on my fit all day, running up and down the stairs etc. Other days I spend hanging out at the climbing gym doing multiple short climbing sessions throughout the day and other days I stay and home and do shores and then go for a 1,5hr walk/jog in the evening. And it varies greatly from week to week.
So as you can see, the amount of "actual" exercise I do varies and most of the exercise I do is low to moderate intensity, however my TDEE is always somewhere around 2000-2200. I base this on my fitbit calculations which I confirmed to be very accurate by tracking my weight changes and intake on a spreadsheet for over a year.
I am 31 y/o, female, 5'2", currently 140 lbs, somewhere around 28-29% body fat based on my Withings scale (probably not super accurate). Since I want to lose around 25lbs, I thought that starting with a deficit somewhere between 250 and 500 would be reasonable, (which I can later reduce to 250) and was planning to eat somewhere between 1600 and 1800 which seems like a totally reasonable intake for a fairly active female, right?
But then I remembered something I read in Lyle McDonald's book on women about energy availability, which determines the adequate intake not simply by counting the deficit, but by taking into account the amount of exercise. Here's the formula:
EA = (Calorie Intake - Exercise Energy Expenditure)/LBM
Here's the thing though, he doesn't explain what count as exercise in this formula. Does walking around all day count? and if so how to calculate it? is there a way to calculate exercise by subtracting, say, the RMR from TDEE?
If so my average exercise calories would be around 500, wich corresponds to the days where my only activity is a walk/jog in the evening. Then according to this formula, my EA is 12cal/lb LBM. But this is actually below the threshold for maintaining a normal reproductive function for women:
So if my estimations for exercise calories are correct according to this formula, I must eat at least 1850 calories, which on an average day would place me only in a 200cal deficit...
So does anyone have any ideas about how to calculate exercise in my case and what an adequate intake in my case would be?
For the context, I am trying to go back to losing weight again and I'm trying to calculate the right intake. The thing is I prefer to use the "TDEE - deficit" method instead of "eating the exercise calories back" because logging exercise would be just too complicated for me. Some days I don't do any "actual exercise" but my job or chores keep me on my fit all day, running up and down the stairs etc. Other days I spend hanging out at the climbing gym doing multiple short climbing sessions throughout the day and other days I stay and home and do shores and then go for a 1,5hr walk/jog in the evening. And it varies greatly from week to week.
So as you can see, the amount of "actual" exercise I do varies and most of the exercise I do is low to moderate intensity, however my TDEE is always somewhere around 2000-2200. I base this on my fitbit calculations which I confirmed to be very accurate by tracking my weight changes and intake on a spreadsheet for over a year.
I am 31 y/o, female, 5'2", currently 140 lbs, somewhere around 28-29% body fat based on my Withings scale (probably not super accurate). Since I want to lose around 25lbs, I thought that starting with a deficit somewhere between 250 and 500 would be reasonable, (which I can later reduce to 250) and was planning to eat somewhere between 1600 and 1800 which seems like a totally reasonable intake for a fairly active female, right?
But then I remembered something I read in Lyle McDonald's book on women about energy availability, which determines the adequate intake not simply by counting the deficit, but by taking into account the amount of exercise. Here's the formula:
EA = (Calorie Intake - Exercise Energy Expenditure)/LBM
Here's the thing though, he doesn't explain what count as exercise in this formula. Does walking around all day count? and if so how to calculate it? is there a way to calculate exercise by subtracting, say, the RMR from TDEE?
If so my average exercise calories would be around 500, wich corresponds to the days where my only activity is a walk/jog in the evening. Then according to this formula, my EA is 12cal/lb LBM. But this is actually below the threshold for maintaining a normal reproductive function for women:
So if my estimations for exercise calories are correct according to this formula, I must eat at least 1850 calories, which on an average day would place me only in a 200cal deficit...
So does anyone have any ideas about how to calculate exercise in my case and what an adequate intake in my case would be?
3
Replies
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As you seem pretty sure your "TDEE is always somewhere around 2000-2200" why not simply just take a modest cut from there?
Say 1800-2000 depending on your lower/higher activity/exercise days?
After a month you will have enough data to adjust if you need to.9 -
Lyle is spot on about EA and this -- and yes, what you're calculating is correct. If a smaller deficit is what you need to keep your bones and health safe, then that's what you need to do.
When I calculating my exercise calories, I take the difference between my sedentary TDEE -- which I've figured out based on my slow weeks/sick weeks -- and then my usual TDEE with my exercise included.
Walking around all day absolutely counts as exercise. Anything above sedentary counts as exercise for these purposes.
Maybe I'm reading too fast and not seeing it. What is your RMR?1 -
This is making my brain hurt. It seems to be unnecessarily over complicating things. First, if you are going to do TDEE, pick a number for your TDEE, and stick with that. The benefit of the TDEE method is that you eat the same amount of calories per day, regardless of how active you are, as your activity over a period of time is averaged into it, not on a specific day. I do TDEE, and my intake targets are the same whether I sit in the office all day or go to my 90 minute martial arts class. I will have smaller deficits on my rest days and larger deficits on my exercise days, but it evens out.
So first start with a number. Then give yourself a 300-400 calorie deficit from that number. That will be your daily target. Track how it makes you feel and if you are feeling like you have a sufficient amount of energy. I would focus on maintaining a reasonable and moderate deficit, and not worry about some unnecessarily complicated formula Lyle McDonald came up with to sell books.
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This is making my brain hurt. It seems to be unnecessarily over complicating things. First, if you are going to do TDEE, pick a number for your TDEE, and stick with that. The benefit of the TDEE method is that you eat the same amount of calories per day, regardless of how active you are, as your activity over a period of time is averaged into it, not on a specific day. I do TDEE, and my intake targets are the same whether I sit in the office all day or go to my 90 minute martial arts class. I will have smaller deficits on my rest days and larger deficits on my exercise days, but it evens out.
So first start with a number. Then give yourself a 300-400 calorie deficit from that number. That will be your daily target. Track how it makes you feel and if you are feeling like you have a sufficient amount of energy. I would focus on maintaining a reasonable and moderate deficit, and not worry about some unnecessarily complicated formula Lyle McDonald came up with to sell books.
Owning my disagree. Maybe not for men, but for women this is a legit concern -- and it's something that's backed up in *numerous* peer-reviewed articles and journals. Lyle didn't come up with this, but he's got one of the more user-friendly guides to understanding it.
I don't expect a man to be as aware of these issues. But that doesn't mean it's made up or "unnecessarily complicated".
Better for the OP to ask these questions now than to come back in a few months asking why she lost her period -- and thus putting herself at risk for osteoporosis down the road.5 -
collectingblues wrote: »Lyle is spot on about EA and this -- and yes, what you're calculating is correct. If a smaller deficit is what you need to keep your bones and health safe, then that's what you need to do.
When I calculating my exercise calories, I take the difference between my sedentary TDEE -- which I've figured out based on my slow weeks/sick weeks -- and then my usual TDEE with my exercise included.
Walking around all day absolutely counts as exercise. Anything above sedentary counts as exercise for these purposes.
Maybe I'm reading too fast and not seeing it. What is your RMR?
My RMR is 1550 according to an online calculator which seems to correspond to my sedentary TDEE. If so, then yes, my EA calculations are correct.0 -
This is making my brain hurt. It seems to be unnecessarily over complicating things. First, if you are going to do TDEE, pick a number for your TDEE, and stick with that. The benefit of the TDEE method is that you eat the same amount of calories per day, regardless of how active you are, as your activity over a period of time is averaged into it, not on a specific day. I do TDEE, and my intake targets are the same whether I sit in the office all day or go to my 90 minute martial arts class. I will have smaller deficits on my rest days and larger deficits on my exercise days, but it evens out.
So first start with a number. Then give yourself a 300-400 calorie deficit from that number. That will be your daily target. Track how it makes you feel and if you are feeling like you have a sufficient amount of energy. I would focus on maintaining a reasonable and moderate deficit, and not worry about some unnecessarily complicated formula Lyle McDonald came up with to sell books.collectingblues wrote: »Owning my disagree. Maybe not for men, but for women this is a legit concern -- and it's something that's backed up in *numerous* peer-reviewed articles and journals. Lyle didn't come up with this, but he's got one of the more user-friendly guides to understanding it.
I don't expect a man to be as aware of these issues. But that doesn't mean it's made up or "unnecessarily complicated".
Better for the OP to ask these questions now than to come back in a few months asking why she lost her period -- and thus putting herself at risk for osteoporosis down the road.
Yeah, I've lost my period due to undereating in the past, I don't want it to happen again. Another reason for me "complicating things" in this way is that I've been struggling with an excessive hunger/hunger-like sensation for quite a while now (medically unexplained so far) and if I want to try and still lose weight by ignoring it, I want to at least be sure that it's not due to undereating and that my intake is adequate.
@collectingblues thank you for your reply!5 -
collectingblues wrote: »Lyle is spot on about EA and this -- and yes, what you're calculating is correct. If a smaller deficit is what you need to keep your bones and health safe, then that's what you need to do.
When I calculating my exercise calories, I take the difference between my sedentary TDEE -- which I've figured out based on my slow weeks/sick weeks -- and then my usual TDEE with my exercise included.
Walking around all day absolutely counts as exercise. Anything above sedentary counts as exercise for these purposes.
Maybe I'm reading too fast and not seeing it. What is your RMR?
My RMR is 1550 according to an online calculator which seems to correspond to my sedentary TDEE. If so, then yes, my EA calculations are correct.
RMR is just barely above BMR per formula estimates.
Sedentary TDEE is going to be more than that though - MFP's BMR x 1.25 is based on recent (compared to Harris 1919 study) WHO studies.
And ditto's to this being a smart study suggested method of getting some initial numbers to work with that isn't aiming below the potentially safe line.
In the end though - it may be the same as what is considered a reasonable deficit.2 -
RMR is just barely above BMR per formula estimates.
Sedentary TDEE is going to be more than that though - MFP's BMR x 1.25 is based on recent (compared to Harris 1919 study) WHO studies.
And ditto's to this being a smart study suggested method of getting some initial numbers to work with that isn't aiming below the potentially safe line.
In the end though - it may be the same as what is considered a reasonable deficit.
Thanks! Yeah, in that case my sedentary TDEE is roughly 1650. So I can calculate my exercise calories from there then.
However there's something that doesn't add up here. My yesterday's TDEE (according to my fitbit) is 2150. If my sedentary TDEE is 1650, then my exercise calories are 500. So how much would I need to eat to have what is considered an "adequate intake" in Lyle's table (20cals/LBM)? If my LBM is 99,4lbs than I would have to eat almost 2500 calories, which is above my TDEE by 350 calories! Something is off here. Either I'm not counting my exercise calories right, or I'm mistaken about my LBM or Lyle's numbers don't make sense...
0 -
RMR is just barely above BMR per formula estimates.
Sedentary TDEE is going to be more than that though - MFP's BMR x 1.25 is based on recent (compared to Harris 1919 study) WHO studies.
And ditto's to this being a smart study suggested method of getting some initial numbers to work with that isn't aiming below the potentially safe line.
In the end though - it may be the same as what is considered a reasonable deficit.
Thanks! Yeah, in that case my sedentary TDEE is roughly 1650. So I can calculate my exercise calories from there then.
However there's something that doesn't add up here. My yesterday's TDEE (according to my fitbit) is 2150. If my sedentary TDEE is 1650, then my exercise calories are 500. So how much would I need to eat to have what is considered an "adequate intake" in Lyle's table (20cals/LBM)? If my LBM is 99,4lbs than I would have to eat almost 2500 calories, which is above my TDEE by 350 calories! Something is off here. Either I'm not counting my exercise calories right, or I'm mistaken about my LBM or Lyle's numbers don't make sense...
The number you want to aim for at a minimum is the menstrual threshold -- adequate would take you to almost maintenance, yes. In kg, the recommended amount for a threshold would be 30 kcal per kg. Adequate is 44 kcal per kg.
Most of these calculations and assumptions presume that an optimal body is not in a state of deficit. That's why there's such a difference between "adequate" and minimal threshold. I don't know why the adequate comes out ~300 above your TDEE in this case, but perhaps the formula thinks that TDEE would increase because of increases in NEAT and TEF. ::shrugs:: I dunno.
Math brain dump ahead... I did these in kg, because that's what most of the literature uses when talking about EA.
When I look at your figures, this is what I come up with:
LBM: 44.54 kg -- I just rounded up to 30 percent body fat
44.54 * 30kcal = 1336 pre-exercise
So that tells us that if you were to do *nothing* every day, you need 1336 for the menstrual threshold. If you do burn 500 calories from exercise every day, you need to take it up to 1836 calories to keep the levels even.
For some reverse math, we know that your sedentary TDEE is 1650, and your normal active is 2150.
If those are both correct, we know that your BMR -- using a sedentary factor of 1.25 -- is likely around 1320, That's about as expected for your weight and body fat percentage. That gives you an everyday activity factor of ~1.63. According to most scales, that works out to a little less than one hour of intense/moderate exercise everyday, plus your normal activities.
This calculator may help, too: https://www.femaleandmaleathletetriad.org/athletes/energy-availability-calculator/
When you reverse the calculations there, and figure an hour of intense exercise *instead* of the 500, the 1836 is indeed right at 31 calories per kilo.6 -
collectingblues wrote: »
The number you want to aim for at a minimum is the menstrual threshold -- adequate would take you to almost maintenance, yes. In kg, the recommended amount for a threshold would be 30 kcal per kg. Adequate is 44 kcal per kg.
Most of these calculations and assumptions presume that an optimal body is not in a state of deficit. That's why there's such a difference between "adequate" and minimal threshold. I don't know why the adequate comes out ~300 above your TDEE in this case, but perhaps the formula thinks that TDEE would increase because of increases in NEAT and TEF. ::shrugs:: I dunno.
Math brain dump ahead... I did these in kg, because that's what most of the literature uses when talking about EA.
When I look at your figures, this is what I come up with:
LBM: 44.54 kg -- I just rounded up to 30 percent body fat
44.54 * 30kcal = 1336 pre-exercise
So that tells us that if you were to do *nothing* every day, you need 1336 for the menstrual threshold. If you do burn 500 calories from exercise every day, you need to take it up to 1836 calories to keep the levels even.
For some reverse math, we know that your sedentary TDEE is 1650, and your normal active is 2150.
If those are both correct, we know that your BMR -- using a sedentary factor of 1.25 -- is likely around 1320, That's about as expected for your weight and body fat percentage. That gives you an everyday activity factor of ~1.63. According to most scales, that works out to a little less than one hour of intense/moderate exercise everyday, plus your normal activities.
This calculator may help, too: https://www.femaleandmaleathletetriad.org/athletes/energy-availability-calculator/
When you reverse the calculations there, and figure an hour of intense exercise *instead* of the 500, the 1836 is indeed right at 31 calories per kilo.
Wow, thanks so much for helping me with the math ! The link you gave is really helpful because it seems to take the exercise intensity into account somehow. The lower the intensity, the higher the EA it seems. So since most of the exercise I do is lower intensity, I can get away with eating slightly less than with the same calories burned by higher intensity exercise, but either way 1850 seems to be the minimum I should aim for. Thanks again!2 -
You have been gaining weight so the numbers may indeed be right; but, do keep in mind that Fitbit can underestimate (just like it can overestimate, or be just right)
This is especially true if a lot of your movement is not captured by Fitbit because it falls below thresholds. F.e. stepping softly with no arm movement, or if you remain standing and only take one or two steps at a time.6 -
collectingblues wrote: »This is making my brain hurt. It seems to be unnecessarily over complicating things. First, if you are going to do TDEE, pick a number for your TDEE, and stick with that. The benefit of the TDEE method is that you eat the same amount of calories per day, regardless of how active you are, as your activity over a period of time is averaged into it, not on a specific day. I do TDEE, and my intake targets are the same whether I sit in the office all day or go to my 90 minute martial arts class. I will have smaller deficits on my rest days and larger deficits on my exercise days, but it evens out.
So first start with a number. Then give yourself a 300-400 calorie deficit from that number. That will be your daily target. Track how it makes you feel and if you are feeling like you have a sufficient amount of energy. I would focus on maintaining a reasonable and moderate deficit, and not worry about some unnecessarily complicated formula Lyle McDonald came up with to sell books.
Owning my disagree. Maybe not for men, but for women this is a legit concern -- and it's something that's backed up in *numerous* peer-reviewed articles and journals. Lyle didn't come up with this, but he's got one of the more user-friendly guides to understanding it.
I don't expect a man to be as aware of these issues. But that doesn't mean it's made up or "unnecessarily complicated".
Better for the OP to ask these questions now than to come back in a few months asking why she lost her period -- and thus putting herself at risk for osteoporosis down the road.
Owning my disagree. OP's TDEE calculation based on her own data accounts for any gender or idiosyncratic variations in energy use. Plus, her planned deficit is fairly conservative (I'd go with 1800 myself based on her numbers.)
2
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