female dietry requirments
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I wrote a big long asnwer and then got a server error that lost my post.
I'll try re-writing it a bit later.
I'll try re-writing it a bit later.
Mindwraith
New Member
Well if there's a big long answer I'd love to know as well.
I
imported_diznik
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me three.
Mindwraith
New Member
Bump
Women generally have 5-10% lower BMR and greater fat percentage so these things must be accounted for when planning a diet. I don't consider bodyweight to be a reliable way of estimating caloric needs because of varying bodyfat levels.
High-protein hypocaloric diets may promote calcium loss and this is especially important for women. Female athletes will probably need extra calcium & iron supplementation.
Most gender differences in performance can be explained by the different body fat / lean mass levels and so nutrition can be adjusted accordingly. However there are other less important differences. For example, men perform slightly better with higher carbohydrates because they can synthesize glycogen more easily (because of higher testosterone). Consequently, women mobilize fats better. There are a few other differences that have to do with the menstrual cycle.
High-protein hypocaloric diets may promote calcium loss and this is especially important for women. Female athletes will probably need extra calcium & iron supplementation.
Most gender differences in performance can be explained by the different body fat / lean mass levels and so nutrition can be adjusted accordingly. However there are other less important differences. For example, men perform slightly better with higher carbohydrates because they can synthesize glycogen more easily (because of higher testosterone). Consequently, women mobilize fats better. There are a few other differences that have to do with the menstrual cycle.
Mindwraith
New Member
[b said:
What would be a reliable way?
For beginners, the first step would be estimating bf level & lean mass and working from there (there are several formulas for estimating your caloric needs from lbm). But in any case this would be only a starting point since caloric requirements can very tremendously among people, not to mention different levels of activity. So, one would have sooner or later to track body weight vs calories ingested and see in practice how much s/he gains or loses. My brother for example, is 15kg lighter than me and I estimate he would need 1000 kcals more than me should he wanted to bulk up.
Micmic
depends on the BF of the person, since BMR generally tracks pretty well with total bodyweight, taking caloric estimates from LBM on an obese person generally will undercut caloric requirements by a fair bit. a good BMR equation will also use the lbm and fat mass for estimates, but the best one for athletes just goes from total bodyweight, as on a lean person it makes little to no difference.
depends on the BF of the person, since BMR generally tracks pretty well with total bodyweight, taking caloric estimates from LBM on an obese person generally will undercut caloric requirements by a fair bit. a good BMR equation will also use the lbm and fat mass for estimates, but the best one for athletes just goes from total bodyweight, as on a lean person it makes little to no difference.
Yes, adipose tissue is not inactive but it doesn't really matter. Its contribution to REE is not half of muscle's anyway. It is much less.
This study tried to develop equations that predict REE from both fat free mass and fat mass, and as you can see the conclusion is that "FM explained only a small part of the variation remaining after FFM was accounted for". Even in the equations where FM was accounted for, lean mass was about 7 times more important than FFM.
So, Resting Energy Expenditure does not correlate well with total body weight for obese persons. For example, a common rule of thumb around the net is to multiply your bw x 15 for maintainance. For a 30yo, 6ft tall person of 220lbs / 30% fat, this would give a maintainance level of 3300 kcal. If the same person uses the Harris-Benedict formula which estimates BMR from lean body mass and uses a modifier 1.2 for a sedentary lifestyle, the maintainance level will be around 2300 kcal. The same number of calories is predicted by the equations in the Nelson et al. study. That is, even if we account for the fat mass, nothing changes. Of course, no matter what modifier we use, I can always show that lean mass is a much better predictor of REE than body weight.
This study tried to develop equations that predict REE from both fat free mass and fat mass, and as you can see the conclusion is that "FM explained only a small part of the variation remaining after FFM was accounted for". Even in the equations where FM was accounted for, lean mass was about 7 times more important than FFM.
So, Resting Energy Expenditure does not correlate well with total body weight for obese persons. For example, a common rule of thumb around the net is to multiply your bw x 15 for maintainance. For a 30yo, 6ft tall person of 220lbs / 30% fat, this would give a maintainance level of 3300 kcal. If the same person uses the Harris-Benedict formula which estimates BMR from lean body mass and uses a modifier 1.2 for a sedentary lifestyle, the maintainance level will be around 2300 kcal. The same number of calories is predicted by the equations in the Nelson et al. study. That is, even if we account for the fat mass, nothing changes. Of course, no matter what modifier we use, I can always show that lean mass is a much better predictor of REE than body weight.
While its fun having a conversation
your wrong
1) the population in that piece of research is normal average weight, not obese, which is waht i mentioned when I said
For example more current research
Nielsen S, Hensrud DD, Romanski S, Levine JA, Burguera B, Jenson MD. Body composition and resting enegy expenditure in humans: role of fat, fat-free mass and extracellular fluid In J Obes Relat Metab 2000;24:1153-7
and a nice quote from the full text.
"Expressing REE relative to FFM alone might introduce errors when lean and obese populations are compared because adipose tissue is an energy requiring tissue"
A lot of the earlier work involved measuring BF with skinfolds or at the very best hydrostatic, and they are not as good as DEXA in the small figures we are looking at. (mainly due to the shitty equations that sf and hydro use. The DEXA also takes into account the fat cell as a part of adipose rather than just the TAGs themselves) Also variability in methods for REE analysis vary between research. I have a list of papers that show no and some effect of FM on REE, but little seem to work with obese subjects.
And in terms of my BF being 1/2 the caloric cost of muscle, i forgot where I got my figures from, and basically it was 1/2 the value of FFM in the regression equation for this study (in both men and women)
Fat is ~1/4 or less when compared to muscle, but it depends on a few variables in the equations.
your wrong
1) the population in that piece of research is normal average weight, not obese, which is waht i mentioned when I said
You cannot extrapolate from that research, becuase if FM is insignificant in a person with average BF, it doesnt mean that the same will apply in subjects with much more BF.[b said:
For example more current research
Nielsen S, Hensrud DD, Romanski S, Levine JA, Burguera B, Jenson MD. Body composition and resting enegy expenditure in humans: role of fat, fat-free mass and extracellular fluid In J Obes Relat Metab 2000;24:1153-7
and a nice quote from the full text.
"Expressing REE relative to FFM alone might introduce errors when lean and obese populations are compared because adipose tissue is an energy requiring tissue"
A lot of the earlier work involved measuring BF with skinfolds or at the very best hydrostatic, and they are not as good as DEXA in the small figures we are looking at. (mainly due to the shitty equations that sf and hydro use. The DEXA also takes into account the fat cell as a part of adipose rather than just the TAGs themselves) Also variability in methods for REE analysis vary between research. I have a list of papers that show no and some effect of FM on REE, but little seem to work with obese subjects.
And in terms of my BF being 1/2 the caloric cost of muscle, i forgot where I got my figures from, and basically it was 1/2 the value of FFM in the regression equation for this study (in both men and women)
Fat is ~1/4 or less when compared to muscle, but it depends on a few variables in the equations.
I don't think so[b said:Quote[/b] (Aaron_F @ Mar. 16 2004,6:05)]While its fun having a conversation
your wrong
If we study Mr. John Doe and his specific REE, then of course we will find a lot of things contributing to his REE. And it will not just be his FFM and FM, it might also be his age, his HR, his insulin, etc. But this still doesn't change what I say. This conversation started as a debate on whether LBM or BW are better predictors of REE on obese people. And how should someone better estimate his caloric needs. So we have two obese persons, both weigh 100kg but one is 25%, the other is 35%. I maintain that their LBM will be a much better predictor of their REE than BW. Would you suggest they use BW ?
BTW, all textbooks I have agree with me, I can quote them. And there are many studies that corroborate this, like this one (which also included obese people), where the conclusion is that "Fat-free mass (FFM) was the best single predictor of REE".
What you say that if we make clinical or laboratory calculations of REE then we have to also take FM into account, which is something I agree with. But for estimations like the ones beginners make, LBM is far more reliable than BW.
your still wrong
Studies in favour of your view, that FM doesnt play a significant role in REE
1) Cunningham JJ. Bodycomposition as a determinant of energy expenditure: a synthetic review and a proposed general prediction equation. Am J Clin Nutr 1991;54:963-9
2) Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr 1990;51:241-7
3) Ferraro R, Ravussin E. Fat mass in predicting resting metabolic rate. Am J Clin Nutr 1992;56:848-56
4) Cunningham JJ. A reanalysis of the factors influencing basal metabolic rate in normal adults. Am J Clin Nutr 1980;33:2372-4
5) Ravussin E, Lillioja S, Anderson TE, Christin L, Bogardus C. Determinants of 24-hour energy expenditure in man. Methods and results using a respiratory Chamber. J Clin Invest 1986;78:1586-78
Articles in Favour of my point of view that FM can play a significant role in REE
6) Nelson KM, Weinsier RL, Long CL, Schulz Y. Prediction of resting energy expenditure from fat-free and fat mass. Am J Clin Nutr 1992;56:848-56
7) Garrow JS, Webster J. Are pre-obese people energy thrifty? Lancet 1985;1:670-1
8) Nielsen S, Hensrud DD, Romanski S, Levine JA, Burguera B, Jenson MD. Body composition and resting enegy expenditure in humans: role of fat, fat-free mass and extracellular fluid In J Obes Relat Metab 2000;24:1153-7
9) Bernstein RS, Thornton JC, Yang MU. Prediction of resting metabolic rate in obese patients. Am J Clin Nutr 1983;37:595-602
10) Dionne I, Despres JP< Bouchard C, Tremblay A. Gender difference in the effect of body composition on energy metabolism. Int J Obes Relat Metab Disord 1999;23:312-9
But, the main differences in a few of these studies is that a fewof the ones that showed a significant effect of FM on REE involved the study of obese subjects.
The interesting thing to note is the studies listed here as 1 and 2 (the one you referenced) make suggestions that the contribution of FM to REE would only become significant when the FM increases above normal, ie Obesity. THis was also noted in study #9
Another interesting paper showed that at baseline, FM wasnt a predictor of REE once FFM was entered into the regression equation. However, after weight loss, there was a greater change in REE than could be explained by FFM alone. Because there was such a change in FM the drop in FM contributed significantly to the change in REE. So while it may not show up in intial calculations from some of these studies, it doesnt nessecarily mean that it is not having an effect.
Heshka S, Yang M, Wang J, Burt P, Pi-Sunyer FX. Weight kiss abd change in resting metabolic rate. Am J Clin Nutr 1990;52:981-6
I have one that tells me that ketosis is a dangerous state to be in (and not diabetic ketoacidosis).
If we have 2 beginers (use a PAL of 1.3 for normalities sake, and age of 25, height 1.6m)
Subject 1: FFM: 50kg FM:15kg BF: 23%
Subject 2: FFM: 50kg FM:50kg BF: 50%
Going from a male equation that includes BF as a predictor gives me (Nielson equation, male)
Subject 1: REE: 1655x1.3 = TEE of ~2159
Subject 2: REE: 1928x1.3 = TEE of ~2506
or approximately 16% difference.
I have met people much bigger (and fatter) than that.
On an 'average' person its pretty much ok to start from LBM, but not everyone.
Throwing the same data into a bunch of other REE (BMR etc) equations that I have on spreadsheet, it gives a range of 1280 - 2209 for the fat and 800 - 1600 or potentially 400kcals of difference
THe equations include Harris, Owen (2 types), Mifflin, Cunningham and the WHO.
Including FM in the equation can be important for a fattie..
And in terms of using BW or LBM as a starting point for REE/TEE
What is the most easily, and reliably measured?
Studies in favour of your view, that FM doesnt play a significant role in REE
1) Cunningham JJ. Bodycomposition as a determinant of energy expenditure: a synthetic review and a proposed general prediction equation. Am J Clin Nutr 1991;54:963-9
2) Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr 1990;51:241-7
3) Ferraro R, Ravussin E. Fat mass in predicting resting metabolic rate. Am J Clin Nutr 1992;56:848-56
4) Cunningham JJ. A reanalysis of the factors influencing basal metabolic rate in normal adults. Am J Clin Nutr 1980;33:2372-4
5) Ravussin E, Lillioja S, Anderson TE, Christin L, Bogardus C. Determinants of 24-hour energy expenditure in man. Methods and results using a respiratory Chamber. J Clin Invest 1986;78:1586-78
Articles in Favour of my point of view that FM can play a significant role in REE
6) Nelson KM, Weinsier RL, Long CL, Schulz Y. Prediction of resting energy expenditure from fat-free and fat mass. Am J Clin Nutr 1992;56:848-56
7) Garrow JS, Webster J. Are pre-obese people energy thrifty? Lancet 1985;1:670-1
8) Nielsen S, Hensrud DD, Romanski S, Levine JA, Burguera B, Jenson MD. Body composition and resting enegy expenditure in humans: role of fat, fat-free mass and extracellular fluid In J Obes Relat Metab 2000;24:1153-7
9) Bernstein RS, Thornton JC, Yang MU. Prediction of resting metabolic rate in obese patients. Am J Clin Nutr 1983;37:595-602
10) Dionne I, Despres JP< Bouchard C, Tremblay A. Gender difference in the effect of body composition on energy metabolism. Int J Obes Relat Metab Disord 1999;23:312-9
But, the main differences in a few of these studies is that a fewof the ones that showed a significant effect of FM on REE involved the study of obese subjects.
The interesting thing to note is the studies listed here as 1 and 2 (the one you referenced) make suggestions that the contribution of FM to REE would only become significant when the FM increases above normal, ie Obesity. THis was also noted in study #9
Another interesting paper showed that at baseline, FM wasnt a predictor of REE once FFM was entered into the regression equation. However, after weight loss, there was a greater change in REE than could be explained by FFM alone. Because there was such a change in FM the drop in FM contributed significantly to the change in REE. So while it may not show up in intial calculations from some of these studies, it doesnt nessecarily mean that it is not having an effect.
Heshka S, Yang M, Wang J, Burt P, Pi-Sunyer FX. Weight kiss abd change in resting metabolic rate. Am J Clin Nutr 1990;52:981-6
textbooks are not exactly sources of unbiased information[b said:
I have one that tells me that ketosis is a dangerous state to be in (and not diabetic ketoacidosis).If we have 2 beginers (use a PAL of 1.3 for normalities sake, and age of 25, height 1.6m)
Subject 1: FFM: 50kg FM:15kg BF: 23%
Subject 2: FFM: 50kg FM:50kg BF: 50%
Going from a male equation that includes BF as a predictor gives me (Nielson equation, male)
Subject 1: REE: 1655x1.3 = TEE of ~2159
Subject 2: REE: 1928x1.3 = TEE of ~2506
or approximately 16% difference.
I have met people much bigger (and fatter) than that.
On an 'average' person its pretty much ok to start from LBM, but not everyone.
Throwing the same data into a bunch of other REE (BMR etc) equations that I have on spreadsheet, it gives a range of 1280 - 2209 for the fat and 800 - 1600 or potentially 400kcals of difference
THe equations include Harris, Owen (2 types), Mifflin, Cunningham and the WHO.
Including FM in the equation can be important for a fattie..
And in terms of using BW or LBM as a starting point for REE/TEE
What is the most easily, and reliably measured?
You keep saying I'm wrong, but then you post things that show I'm right What exactly is it that I'm wrong about ? My assertion was that LBM will be a much better predictor of REE than BW, and a beginner looking for a caloric estimation should better use his LBM. I know that there are a lot of studies that can support anything you want, but this is irrelevant. These studies are of no value to the beginner looking for his REE estimation. So, I repeat the example of two 100kg men, 25% and 35%. Or any other example for that matter.
What I would suggest is after an estimation of LBM with calipers, to use the Katch-McArdle formula: BMR = 370 + (21.6 * LBM in kg). This would give a BMR of about 1990 kcals for the 25% guy, and about 1770 kcals for the 35% guy.
What would you suggest ?
What exactly is it that I'm wrong about ? My assertion was that LBM will be a much better predictor of REE than BW, and a beginner looking for a caloric estimation should better use his LBM. I know that there are a lot of studies that can support anything you want, but this is irrelevant. These studies are of no value to the beginner looking for his REE estimation. So, I repeat the example of two 100kg men, 25% and 35%. Or any other example for that matter. What I would suggest is after an estimation of LBM with calipers, to use the Katch-McArdle formula: BMR = 370 + (21.6 * LBM in kg). This would give a BMR of about 1990 kcals for the 25% guy, and about 1770 kcals for the 35% guy.
What would you suggest ?
Mindwraith
New Member
Ok first of all what is:
FM?
REE?
TEE?
Second of all, how do you determine fat free mass? I would assume I figure out my body fat percentage and subtract that from total weight? Of course that would still include bones and organs.
FM?
REE?
TEE?
Second of all, how do you determine fat free mass? I would assume I figure out my body fat percentage and subtract that from total weight? Of course that would still include bones and organs.
Look here for TEE, REE, etc. FM is fat mass, FFM is fat free mass. If you have estimated your bodyfat level you already know your fat mass. If for example you weigh 180lbs and you are 15%, then your FM is 180*0.15 = 27lbs. The rest of it, 180-27=153lbs is your Fat Free Mass, FFM. Yes, FFM includes everything that isn't fat.
Um, you went off on another tangent obviously[b said:Quote[/b] (micmic @ Mar. 17 2004,12:14)]You keep saying I'm wrong, but then you post things that show I'm right
I was taking exception to your comment
which it clearly does in the people I was talking about, the obese.[b said:
Bodyweight is the simplest method to get a caloric estimationfrom, as any method of measuring LBM is covered with the usual assumptions, and is definately easier to jump on a scale for the average beginer than it is to get a accurate BF measurement.