Study suggests you can run larger deficit than we think?
jonnythan
Posts: 10,161 Member
http://www.sciencedirect.com/science/article/pii/S0022519304004175
"A limit on the maximum energy transfer rate from the human fat store in hypophagia is deduced from experimental data of underfed subjects maintaining moderate activity levels and is found to have a value of (290+/-25) kJ/kgd. A dietary restriction which exceeds the limited capability of the fat store to compensate for the energy deficiency results in an immediate decrease in the fat free mass (FFM). In cases of a less severe dietary deficiency, the FFM will not be depleted."
In other words, the maximum amount of energy you can transfer out of fat stores is 265-315 kJ (63-75 calories) per kg of fat per day.
For a 150-lb woman with 30% body fat, that means that the maximum energy from fat stores is between 1288 and 1534 calories per day. Likewise, a 200-lb man with 12% body fat can get a maximum if 687 to 817 calories from fat mass per day.
The suggestion here is that our theoretical woman can approach a 1200 calorie a day deficit without sacrificing a great deal of lean mass. The abstract suggests a transition zone from FM (fat mass) loss to FFM (fat free mass) loss, but doesn't go into detail about it. Does anyone have access to the rest of the article?
"A limit on the maximum energy transfer rate from the human fat store in hypophagia is deduced from experimental data of underfed subjects maintaining moderate activity levels and is found to have a value of (290+/-25) kJ/kgd. A dietary restriction which exceeds the limited capability of the fat store to compensate for the energy deficiency results in an immediate decrease in the fat free mass (FFM). In cases of a less severe dietary deficiency, the FFM will not be depleted."
In other words, the maximum amount of energy you can transfer out of fat stores is 265-315 kJ (63-75 calories) per kg of fat per day.
For a 150-lb woman with 30% body fat, that means that the maximum energy from fat stores is between 1288 and 1534 calories per day. Likewise, a 200-lb man with 12% body fat can get a maximum if 687 to 817 calories from fat mass per day.
The suggestion here is that our theoretical woman can approach a 1200 calorie a day deficit without sacrificing a great deal of lean mass. The abstract suggests a transition zone from FM (fat mass) loss to FFM (fat free mass) loss, but doesn't go into detail about it. Does anyone have access to the rest of the article?
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Replies
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Bump - to see if there is anything to learn.0
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No, Hope someone does.0
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James Krieger does an awesome piece on this in the Feb. Weightology Weekly, but this is paid content unfortunately, so I can't link/copy it here.
I think a big thing to keep in mind is that the study you linked is a hypothesis to suggest a maximum amount of fat you could lose.
Deficit size, as I'm sure you know, is a variable that may effect ones ability to retain LBM. This theoretical limit doesn't say anything about LBM loss. (So even if it's POSSIBLE to figure out this limit and attempt to approach it via larger deficit, that may not necessarily be smart in terms of LBM, dietary adherence, performance, etc).0 -
Too funny - I was just reading a post about this -
A limit on the maximum energy transfer rate from the human fat store in hypophagia is deduced from experimental data of underfed subjects maintaining moderate activity levels and is found to have a value of (290±25) kJ/kg d. A dietary restriction which exceeds the limited capability of the fat store to compensate for the energy deficiency results in an immediate decrease in the fat free mass (FFM). In cases of a less severe dietary deficiency, the FFM will not be depleted. The transition between these two dietary regions is developed and a criterion to distinguish the regions is defined. An exact mathematical solution for the decrease of the FFM is derived for the case where the fat mass (FM) is in its limited energy transfer mode. The solution shows a steady-state term which is in agreement with conventional ideas, a term indicating a slow decrease of much of the FFM moderated by the limited energy transferred from the fat store, and a final term showing an unprotected rapid decrease of the remaining part of the FFM. The average resting metabolic rate of subjects undergoing hypophagia is shown to decrease linearly as a function of the FFM with a slope of (249±25) kJ/kg d. This value disagrees with the results of other observers who have measured metabolic rates of diverse groups. The disagreement is explained in terms of individual metabolic properties as opposed to those of the larger population.
S.S. Alpert Journal of Theoretical Biology Volume 233, Issue 1, 7 March 2005, Pages 1-13
http://www.sciencedirect.com/science/article/pii/S00225193040041750 -
meh
what's the rush?0 -
meh
what's the rush?
i wanna be skinny 10 years ago0 -
No rush - but it could be very useful for folks like me (five feet nothing) who are bumping up against their BMR to create a deficit significant enough to create any appreciable loss.1
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No rush - but it could be very useful for folks like me (five feet nothing) who are bumping up against their BMR to create a deficit significant enough to create any appreciable loss.
Nothing wrong with eating a little below BMR on relatively sedentary days. That's another thread though.0 -
Nothing wrong with eating a little below BMR on relatively sedentary days. That's another thread though.
^ Agreed, despite the uproar it seems to create.0 -
bump0
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As SS eludes to, it's a hypothetical which doesn't translate well in the real world since that hypothetical max deficit would be too large to maintain for nearly all populations regardless of fat mass. My hypothetical max deficit is just over 500 calories. Yet, from previous cuts at 10% body fat, I seem to lose excessive LBM if I go beyond a 400 calorie deficit.0
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Too funny - I was just reading a post about this -
A limit on the maximum energy transfer rate from the human fat store in hypophagia is deduced from experimental data of underfed subjects maintaining moderate activity levels and is found to have a value of (290±25) kJ/kg d. A dietary restriction which exceeds the limited capability of the fat store to compensate for the energy deficiency results in an immediate decrease in the fat free mass (FFM). In cases of a less severe dietary deficiency, the FFM will not be depleted. The transition between these two dietary regions is developed and a criterion to distinguish the regions is defined. An exact mathematical solution for the decrease of the FFM is derived for the case where the fat mass (FM) is in its limited energy transfer mode. The solution shows a steady-state term which is in agreement with conventional ideas, a term indicating a slow decrease of much of the FFM moderated by the limited energy transferred from the fat store, and a final term showing an unprotected rapid decrease of the remaining part of the FFM. The average resting metabolic rate of subjects undergoing hypophagia is shown to decrease linearly as a function of the FFM with a slope of (249±25) kJ/kg d. This value disagrees with the results of other observers who have measured metabolic rates of diverse groups. The disagreement is explained in terms of individual metabolic properties as opposed to those of the larger population.
S.S. Alpert Journal of Theoretical Biology Volume 233, Issue 1, 7 March 2005, Pages 1-13
http://www.sciencedirect.com/science/article/pii/S00225193040041750 -
CAn you guys use simple english please? The intellectually handicap like me have difficulty understanding your complicated language1
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CAn you guys use simple english please? The intellectually handicap like me have difficulty understanding your complicated language
Cliffs:
Dude is all like "Yo I got a theory brah. You can only lose DIS MUCH (*gesture with hands*) fat per day son. Check it. (*bunch of math*). Word.0 -
I have read quite a few studies that support this. In certain studies where protein intake was kept high, nutrients were supplemented, and strength training is conducted, obese women on VLCD's were able to maintain LBM. Considering the fact that intake was regulated between 600-800 calories, I'm sure the deficit was quite large.
I feel like I should say that obviously, the greater the deficit, the more difficult it is to regulate protein and nutrition which is why it's recommended only under supervision of a doctor.
I haven't read this particular study but I'm going to check it out next time I'm on campus (I can probably get access to it through school).0 -
Cliffs:
Dude is all like "Yo I got a theory brah. You can only lose DIS MUCH (*gesture with hands*) fat per day son. Check it. (*bunch of math*). Word.
*nods*0 -
I have read quite a few studies that support this. In certain studies where protein intake was kept high, nutrients were supplemented, and strength training is conducted, obese women on VLCD's were able to maintain LBM. Considering the fact that intake was regulated between 600-800 calories, I'm sure the deficit was quite large.
I feel like I should say that obviously, the greater the deficit, the more difficult it is to regulate protein and nutrition which is why it's recommended only under supervision of a doctor.
I haven't read this particular study but I'm going to check it out next time I'm on campus (I can probably get access to it through school).
Link for study noted above
http://intl.jacn.org/content/18/2/115.full
Effects of Resistance vs. Aerobic Training Combined With an 800 Calorie Liquid Diet on Lean Body Mass and Resting Metabolic Rate0 -
I have read quite a few studies that support this. In certain studies where protein intake was kept high, nutrients were supplemented, and strength training is conducted, obese women on VLCD's were able to maintain LBM. Considering the fact that intake was regulated between 600-800 calories, I'm sure the deficit was quite large.
I feel like I should say that obviously, the greater the deficit, the more difficult it is to regulate protein and nutrition which is why it's recommended only under supervision of a doctor.
I haven't read this particular study but I'm going to check it out next time I'm on campus (I can probably get access to it through school).
I can't find it in my school's library resources. If you could read it and give us some more info that would be pretty rad!0 -
I can't find it in my school's library resources. If you could read it and give us some more info that would be pretty rad!
^^I just linked it (I assume that is the one she is referring to).
Just to point out though - they started with a BF% in excess of 45%0 -
^^I just linked it (I assume that is the one she is referring to).
Just to point out though - they started with a BF% in excess of 45%
Oh I was talking about the one in the OP. I will go check that one out too, thanks.0 -
I can't find it in my school's library resources. If you could read it and give us some more info that would be pretty rad!
When I get online using my schools server, I can usually get into any journal there are some that don't have an agreement with my university so I'm not sure.0 -
Oh I was talking about the one in the OP. I will go check that one out too, thanks.
oop - sorry. :happy:0 -
I have access to the full article, and it's worth noting the following pargraph in the conclusions:The main thesis of this paper is that the FM is able to transfer energy to the FFM up to a maximum rate of (290±25) kJ/kg d. In realistic energy deficit situations, the actual transfer rate is decreased by activity considerations. The value of the maximum transfer rate is derived from data for young, active male subjects studied by Keys et al. (1950). The applicability of these results have not been directly verified in other populations and conditions.
I think the authors are quite clear that they can't draw too many conclusions from their limited study.0 -
^ Agreed, despite the uproar it seems to create.
I'll third that and we'll see who is the first person to mention a coma.0 -
Cliffs:
Dude is all like "Yo I got a theory brah. You can only lose DIS MUCH (*gesture with hands*) fat per day son. Check it. (*bunch of math*). Word.
^nice explanation! but mostly, bump0 -
I have read quite a few studies that support this. In certain studies where protein intake was kept high, nutrients were supplemented, and strength training is conducted, obese women on VLCD's were able to maintain LBM. Considering the fact that intake was regulated between 600-800 calories, I'm sure the deficit was quite large.
I feel like I should say that obviously, the greater the deficit, the more difficult it is to regulate protein and nutrition which is why it's recommended only under supervision of a doctor.
I haven't read this particular study but I'm going to check it out next time I'm on campus (I can probably get access to it through school).
Just some random comments, and I'm not saying this to refute anyone or anything as I find the original study to be quite interesting and the topic in general interests me.
When you say "I have read quite a few studies that support this", I assume you're just talking about the notion of larger calorie deficits being conducive to greater fat loss, and that in some cases we can retain LBM while doing so? Or are you saying that you've seen studies that would support the theoretical limits that the original study suggests? I'm only clarifying because the original study (at least, to me) constructs a model to predict maximum amount of fat that can be oxidized per day based on weight.
[/quote]It is probably this one
http://intl.jacn.org/content/18/2/115.full
Effects of Resistance vs. Aerobic Training Combined With an 800 Calorie Liquid Diet on Lean Body Mass and Resting Metabolic Rate
[/quote]
And regarding both the above study and the previous comments about VLCD's and LBM retention, I would obviously assume that in both cases (the above study and the previous comments) we are talking about obese and untrained individuals who are put on a resistance program. Both of these are pretty much optimal conditions under which one would stand the greatest chance of favorable results as far as LBM maintenance.
EDIT: Sara just pointed out their bodyfat% in a previous reply, presumably for the same reason.0 -
Fourth that and I'd love to read both articles.0
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Cliffs:
Dude is all like "Yo I got a theory brah. You can only lose DIS MUCH (*gesture with hands*) fat per day son. Check it. (*bunch of math*). Word.
Best summary I ever read!
(not a single experiment actually done! ... as was said, don't read too much into it)0 -
So, I can run a daily deficit of a few thousand? Good, that whole eating thing was getting old!0
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I have access to the full article, and it's worth noting the following pargraph in the conclusions:
I think the authors are quite clear that they can't draw too many conclusions from their limited study.
Ahh thanks for that. I thought the reference to "experimental data" in the first sentence was from their own experiment, not an older one. I was hoping the body of the paper would include more data. Oh well.0
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