Guest guest Posted December 8, 2005 Report Share Posted December 8, 2005 Very interesting article Al. I think that Professor Leibel states the same thing that was found in Keys' starvation studies, i.e., that the Basal Energy Expenditure (BEE) does not go much below 15% even at high degrees of caloric restriction. Although Leibel mentions this in terms of losing a percentage of BODY WEIGHT, rather than in dietary caloric restriction, the conclusion seems clear: Losing more than 10% of body weight will not necessarily give you more than a 15% decrease in BEE. I conclude from this that it is not particularly beneficial to practice CR diets that lower your weight by more than 10% from what your normal weight would be. For example, if your " normal " weight is 160 pounds, you only need to lose 16 pounds to lower your BEE by 15%, and 144 pounds should be your CR goal. >>> SA: Is the relationship more or less linear: when you have people drop by 10 percent does their energy expenditure drop a certain amount, and then when they drop 20 percent in weight, it decreases by twice that amount, and so on? RL: No. That is another very interesting point. When a person goes down 10 percent in body weight, lean or obese their reduction in energy expenditure is in the 15 percent range. If you take them down by 20 percent, it doesn't get any more. So it appears that whatever this defense mechanism is, if you want to look at it teleologically like that, it kicks in quite early: 10 percent is enough to bring it out. We don't know whether five percent is, because we've never tested that small an increase in weight. But [energy expenditure] doesn't reduce any further if you drop them 20 percent, 30 percent, or even as much as 50 percent. >>> As far as the Mifflin-St Jeor equations, they are not obsolete by any means. Here is what Leibel says: >>> You can account for virtually all the energy expenditure in a human by knowing their lean body mass and their physical activity. So we found that a gain in body weight causes the individual to spend more energy than you would predict based on their new lean body mass. >>> Tony > > Hi All, > > Based on an interview with Rudolph L. Leibel: > > http://www.sciam.com/print_version.cfm?articleID=00087E84-E0CB-1CD9-B4A8809EC588\ EEDF > > is calculating %CR " from the -Benedict or Mifflin-St Jeor equations of any > real meaning? > > Al Pater, PhD; email: old542000@y... Quote Link to comment Share on other sites More sharing options...
Guest guest Posted December 8, 2005 Report Share Posted December 8, 2005 Very interesting article Al. I think that Professor Leibel states the same thing that was found in Keys' starvation studies, i.e., that the Basal Energy Expenditure (BEE) does not go much below 15% even at high degrees of caloric restriction. Although Leibel mentions this in terms of losing a percentage of BODY WEIGHT, rather than in dietary caloric restriction, the conclusion seems clear: Losing more than 10% of body weight will not necessarily give you more than a 15% decrease in BEE. I conclude from this that it is not particularly beneficial to practice CR diets that lower your weight by more than 10% from what your normal weight would be. For example, if your " normal " weight is 160 pounds, you only need to lose 16 pounds to lower your BEE by 15%, and 144 pounds should be your CR goal. >>> SA: Is the relationship more or less linear: when you have people drop by 10 percent does their energy expenditure drop a certain amount, and then when they drop 20 percent in weight, it decreases by twice that amount, and so on? RL: No. That is another very interesting point. When a person goes down 10 percent in body weight, lean or obese their reduction in energy expenditure is in the 15 percent range. If you take them down by 20 percent, it doesn't get any more. So it appears that whatever this defense mechanism is, if you want to look at it teleologically like that, it kicks in quite early: 10 percent is enough to bring it out. We don't know whether five percent is, because we've never tested that small an increase in weight. But [energy expenditure] doesn't reduce any further if you drop them 20 percent, 30 percent, or even as much as 50 percent. >>> As far as the Mifflin-St Jeor equations, they are not obsolete by any means. Here is what Leibel says: >>> You can account for virtually all the energy expenditure in a human by knowing their lean body mass and their physical activity. So we found that a gain in body weight causes the individual to spend more energy than you would predict based on their new lean body mass. >>> Tony > > Hi All, > > Based on an interview with Rudolph L. Leibel: > > http://www.sciam.com/print_version.cfm?articleID=00087E84-E0CB-1CD9-B4A8809EC588\ EEDF > > is calculating %CR " from the -Benedict or Mifflin-St Jeor equations of any > real meaning? > > Al Pater, PhD; email: old542000@y... Quote Link to comment Share on other sites More sharing options...
Guest guest Posted December 8, 2005 Report Share Posted December 8, 2005 Hi Tony: I haven't properly studied the article, just skimmed it very quickly. Perhaps I will get to it on the weekend. But mice must be different from humans then? When mice are restricted 40%, weight drops 50%. Now if their BMR drops only 15%, as Leibel appears to claim, then logically, the mice should shrivel up to nothing since they are burning up in BMR calories a lot more than they are taking in? In fact, though, quite the contrary, they thrive, being very energetic and live substantially longer. So, are mice different from humans in this respect? Or is there something faulty in Liebel's data - or in the mice data, of course - or, LOL, in my logic?! Rodney. -- In , " citpeks " <citpeks@y...> quoted: ............................ > RL: No. That is another very interesting point. When a person goes > down 10 percent in body weight, lean or obese their reduction in > energy expenditure is in the 15 percent range. If you take them down > by 20 percent, it doesn't get any more. So it appears that whatever > this defense mechanism is, if you want to look at it teleologically > like that, it kicks in quite early: 10 percent is enough to bring it > out. We don't know whether five percent is, because we've never tested > that small an increase in weight. But [energy expenditure] doesn't > reduce any further if you drop them 20 percent, 30 percent, or even as > much as 50 percent. Quote Link to comment Share on other sites More sharing options...
Guest guest Posted December 8, 2005 Report Share Posted December 8, 2005 Hi Tony: I haven't properly studied the article, just skimmed it very quickly. Perhaps I will get to it on the weekend. But mice must be different from humans then? When mice are restricted 40%, weight drops 50%. Now if their BMR drops only 15%, as Leibel appears to claim, then logically, the mice should shrivel up to nothing since they are burning up in BMR calories a lot more than they are taking in? In fact, though, quite the contrary, they thrive, being very energetic and live substantially longer. So, are mice different from humans in this respect? Or is there something faulty in Liebel's data - or in the mice data, of course - or, LOL, in my logic?! Rodney. -- In , " citpeks " <citpeks@y...> quoted: ............................ > RL: No. That is another very interesting point. When a person goes > down 10 percent in body weight, lean or obese their reduction in > energy expenditure is in the 15 percent range. If you take them down > by 20 percent, it doesn't get any more. So it appears that whatever > this defense mechanism is, if you want to look at it teleologically > like that, it kicks in quite early: 10 percent is enough to bring it > out. We don't know whether five percent is, because we've never tested > that small an increase in weight. But [energy expenditure] doesn't > reduce any further if you drop them 20 percent, 30 percent, or even as > much as 50 percent. Quote Link to comment Share on other sites More sharing options...
Guest guest Posted December 8, 2005 Report Share Posted December 8, 2005 [ ] Re: Whey CR effects A fascinating article,Al. It would be interesting to know whether those using fermented dairy products in their cron practice have experienced much lean mass wasting as the opposite effect seems strongly suggested by the authors(???) of the posted article when consuming dairy in a calorie restricted diet. --I have experienced remarkable lean-mass conservation, and yogurt with brewer's yeast, oat bran, and blueberries is one of my staples. Maco Quote Link to comment Share on other sites More sharing options...
Guest guest Posted December 8, 2005 Report Share Posted December 8, 2005 [ ] Re: Whey CR effects A fascinating article,Al. It would be interesting to know whether those using fermented dairy products in their cron practice have experienced much lean mass wasting as the opposite effect seems strongly suggested by the authors(???) of the posted article when consuming dairy in a calorie restricted diet. --I have experienced remarkable lean-mass conservation, and yogurt with brewer's yeast, oat bran, and blueberries is one of my staples. Maco Quote Link to comment Share on other sites More sharing options...
Guest guest Posted December 8, 2005 Report Share Posted December 8, 2005 I don't think that mice metabolism is too different from humans. Applying the Mifflin-St Jeor energy equations to 50%-size humans shows that they need 60% of the nutrition of full-size humans, i.e., 40% CR, the same as mice. See the bottom of my web page for the calculations: http://www.scientificpsychic.com/health/crondiet.html If you recall, in August of 2004 (Message 14018, What is CRON? - 18% more food?), we had some discussions on this topic. I have been trying to understand the paradox that 40%CR mice and rats eat 18% more food per body weight than ad libitum rodents. I think that the metabolic capacity decreases at a slower rate than body weight as the food calories are restricted. Liebel's data basically confirms the limit of ~15% found by Keys (Keys A, Brozek J, Henschel A, Mickelsen O, HL. " The biology of human starvation " , Minneapolis: University of Minneapolis Press, 1950.) Longevity may depend to some degree on the lowering of metabolic rate, but also on other factors such as amount of adipose tissue, etc., and everything is probably interrelated. The fact that higher CR rates result in longer lifespans, even though metabolic rate bottoms out at -15%, means that the lower metabolic rate is not the only factor for longevity. Tony > > Hi Tony: > > I haven't properly studied the article, just skimmed it very > quickly. Perhaps I will get to it on the weekend. But mice must be > different from humans then? > > When mice are restricted 40%, weight drops 50%. Now if their BMR > drops only 15%, as Leibel appears to claim, then logically, the mice > should shrivel up to nothing since they are burning up in BMR > calories a lot more than they are taking in? In fact, though, quite > the contrary, they thrive, being very energetic and live > substantially longer. > > So, are mice different from humans in this respect? Or is there > something faulty in Liebel's data - or in the mice data, of course - > or, LOL, in my logic?! > > Rodney. > > -- In , " citpeks " <citpeks@y...> quoted: > > ........................... > > RL: No. That is another very interesting point. When a person goes > > down 10 percent in body weight, lean or obese their reduction in > > energy expenditure is in the 15 percent range. If you take them down > > by 20 percent, it doesn't get any more. So it appears that whatever > > this defense mechanism is, if you want to look at it teleologically > > like that, it kicks in quite early: 10 percent is enough to bring it > > out. We don't know whether five percent is, because we've never > tested > > that small an increase in weight. But [energy expenditure] doesn't > > reduce any further if you drop them 20 percent, 30 percent, or even > as > > much as 50 percent. > Quote Link to comment Share on other sites More sharing options...
Guest guest Posted December 8, 2005 Report Share Posted December 8, 2005 I don't think that mice metabolism is too different from humans. Applying the Mifflin-St Jeor energy equations to 50%-size humans shows that they need 60% of the nutrition of full-size humans, i.e., 40% CR, the same as mice. See the bottom of my web page for the calculations: http://www.scientificpsychic.com/health/crondiet.html If you recall, in August of 2004 (Message 14018, What is CRON? - 18% more food?), we had some discussions on this topic. I have been trying to understand the paradox that 40%CR mice and rats eat 18% more food per body weight than ad libitum rodents. I think that the metabolic capacity decreases at a slower rate than body weight as the food calories are restricted. Liebel's data basically confirms the limit of ~15% found by Keys (Keys A, Brozek J, Henschel A, Mickelsen O, HL. " The biology of human starvation " , Minneapolis: University of Minneapolis Press, 1950.) Longevity may depend to some degree on the lowering of metabolic rate, but also on other factors such as amount of adipose tissue, etc., and everything is probably interrelated. The fact that higher CR rates result in longer lifespans, even though metabolic rate bottoms out at -15%, means that the lower metabolic rate is not the only factor for longevity. Tony > > Hi Tony: > > I haven't properly studied the article, just skimmed it very > quickly. Perhaps I will get to it on the weekend. But mice must be > different from humans then? > > When mice are restricted 40%, weight drops 50%. Now if their BMR > drops only 15%, as Leibel appears to claim, then logically, the mice > should shrivel up to nothing since they are burning up in BMR > calories a lot more than they are taking in? In fact, though, quite > the contrary, they thrive, being very energetic and live > substantially longer. > > So, are mice different from humans in this respect? Or is there > something faulty in Liebel's data - or in the mice data, of course - > or, LOL, in my logic?! > > Rodney. > > -- In , " citpeks " <citpeks@y...> quoted: > > ........................... > > RL: No. That is another very interesting point. When a person goes > > down 10 percent in body weight, lean or obese their reduction in > > energy expenditure is in the 15 percent range. If you take them down > > by 20 percent, it doesn't get any more. So it appears that whatever > > this defense mechanism is, if you want to look at it teleologically > > like that, it kicks in quite early: 10 percent is enough to bring it > > out. We don't know whether five percent is, because we've never > tested > > that small an increase in weight. But [energy expenditure] doesn't > > reduce any further if you drop them 20 percent, 30 percent, or even > as > > much as 50 percent. > Quote Link to comment Share on other sites More sharing options...
Guest guest Posted December 8, 2005 Report Share Posted December 8, 2005 Hi Tony: Thanks for that response, but I do not think it answers what I see to be the inherent contradiction between Leibel and the restricted mice experiments. So let me give you a concrete example of this contradiction and let's see if you can show me where the error lies. We agree that the metabolism of mice is not likely to be very different from that of humans. We know that 40%-restricted mice lose 50% of their weight. So let's take the example of a human who embarks on 40% CR at a weight of 200 pounds, and pre-starting caloric intake of 2500 calories, and who exercises 'moderately' (factor 1.375 x BMR): ........Weight.. .......Calories....... ........------...---------------------- ........Pounds...Total...BMR...Activity ........------...-----..-----..-------- Start...200......2500...1818...682 @40%CR..100......1500...1091...409 In the above table line 1 shows him as he starts out at 200 pounds and eating 2500 calories, of which 682 are attributable to his daily physical activity, using the 1.375 factor. Line 2 shows that his weight has fallen 50% - in line with the mouse data - in response to his 40% reduction in calories. At the same activity level this means that 409 calories are now attributable to activity beyond the bedrest level. But now consider what Leibel is telling us. The following line shows the calorie data if Leibel is correct: @40%CR..100......1500...1545...580 Leibel says that 40% CR (from 2500 to 1500 calories) would only drop BMR by 15% at most. A 15% drop in BMR from the original BMR of 1818 is 1545. Applying, again, the 1.375 factor (if anything restricted mice exercise a lot MORE than AL mice, so this number could very well be higher) physical activity comes out at 580 calories. Now you will see we have a problem here. We know that caloric intake has been reduced by 40% to 1500 calories a day, because that was the purpose of the exercise. But these moderately exercising mice, according to Leibel, will be expending more calories just for their BMR than they are consuming each day - let alone before we add in the exercise. When the exercise is added in there is a daily caloric deficit of 625 (the 1545 + 580 = 2125) that Leibel would have us believe are being expended minus the 1500 that we know are being consumed). This individual, after reaching 100 pounds, would weigh ZERO after eighteen months on a 625 calorie daily deficit. Of course long before eighteen months was up he would have crossed the survivability BMI threshold in a downward direction, if he really had a 625 daily caloric deficit. Does this clarify the issue I am raising here? Either Leibel's assertion that BMR does not drop more than 15% is full of it. Or the mice experiments are full of it. Or my logic is full of it. Do we know which? Rodney. > > I don't think that mice metabolism is too different from humans. > Applying the Mifflin-St Jeor energy equations to 50%-size humans shows > that they need 60% of the nutrition of full-size humans, i.e., 40% CR, > the same as mice. See the bottom of my web page for the calculations: > > http://www.scientificpsychic.com/health/crondiet.html > > If you recall, in August of 2004 (Message 14018, What is CRON? - 18% > more food?), we had some discussions on this topic. I have been > trying to understand the paradox that 40%CR mice and rats eat 18% more > food per body weight than ad libitum rodents. I think that the > metabolic capacity decreases at a slower rate than body weight as the > food calories are restricted. Liebel's data basically confirms the > limit of ~15% found by Keys (Keys A, Brozek J, Henschel A, Mickelsen > O, HL. " The biology of human starvation " , Minneapolis: > University of Minneapolis Press, 1950.) > > Longevity may depend to some degree on the lowering of metabolic rate, > but also on other factors such as amount of adipose tissue, etc., and > everything is probably interrelated. The fact that higher CR rates > result in longer lifespans, even though metabolic rate bottoms out at > -15%, means that the lower metabolic rate is not the only factor for > longevity. > > Tony > > > --- In , " Rodney " <perspect1111@y...> wrote: > > > > Hi Tony: > > > > I haven't properly studied the article, just skimmed it very > > quickly. Perhaps I will get to it on the weekend. But mice must be > > different from humans then? > > > > When mice are restricted 40%, weight drops 50%. Now if their BMR > > drops only 15%, as Leibel appears to claim, then logically, the mice > > should shrivel up to nothing since they are burning up in BMR > > calories a lot more than they are taking in? In fact, though, quite > > the contrary, they thrive, being very energetic and live > > substantially longer. > > > > So, are mice different from humans in this respect? Or is there > > something faulty in Liebel's data - or in the mice data, of course - > > or, LOL, in my logic?! > > > > Rodney. > > > > -- In , " citpeks " <citpeks@y...> quoted: > > > > ........................... > > > RL: No. That is another very interesting point. When a person goes > > > down 10 percent in body weight, lean or obese their reduction in > > > energy expenditure is in the 15 percent range. If you take them down > > > by 20 percent, it doesn't get any more. So it appears that whatever > > > this defense mechanism is, if you want to look at it teleologically > > > like that, it kicks in quite early: 10 percent is enough to bring it > > > out. We don't know whether five percent is, because we've never > > tested > > > that small an increase in weight. But [energy expenditure] doesn't > > > reduce any further if you drop them 20 percent, 30 percent, or even > > as > > > much as 50 percent. > > > Quote Link to comment Share on other sites More sharing options...
Guest guest Posted December 8, 2005 Report Share Posted December 8, 2005 Hi Tony: Thanks for that response, but I do not think it answers what I see to be the inherent contradiction between Leibel and the restricted mice experiments. So let me give you a concrete example of this contradiction and let's see if you can show me where the error lies. We agree that the metabolism of mice is not likely to be very different from that of humans. We know that 40%-restricted mice lose 50% of their weight. So let's take the example of a human who embarks on 40% CR at a weight of 200 pounds, and pre-starting caloric intake of 2500 calories, and who exercises 'moderately' (factor 1.375 x BMR): ........Weight.. .......Calories....... ........------...---------------------- ........Pounds...Total...BMR...Activity ........------...-----..-----..-------- Start...200......2500...1818...682 @40%CR..100......1500...1091...409 In the above table line 1 shows him as he starts out at 200 pounds and eating 2500 calories, of which 682 are attributable to his daily physical activity, using the 1.375 factor. Line 2 shows that his weight has fallen 50% - in line with the mouse data - in response to his 40% reduction in calories. At the same activity level this means that 409 calories are now attributable to activity beyond the bedrest level. But now consider what Leibel is telling us. The following line shows the calorie data if Leibel is correct: @40%CR..100......1500...1545...580 Leibel says that 40% CR (from 2500 to 1500 calories) would only drop BMR by 15% at most. A 15% drop in BMR from the original BMR of 1818 is 1545. Applying, again, the 1.375 factor (if anything restricted mice exercise a lot MORE than AL mice, so this number could very well be higher) physical activity comes out at 580 calories. Now you will see we have a problem here. We know that caloric intake has been reduced by 40% to 1500 calories a day, because that was the purpose of the exercise. But these moderately exercising mice, according to Leibel, will be expending more calories just for their BMR than they are consuming each day - let alone before we add in the exercise. When the exercise is added in there is a daily caloric deficit of 625 (the 1545 + 580 = 2125) that Leibel would have us believe are being expended minus the 1500 that we know are being consumed). This individual, after reaching 100 pounds, would weigh ZERO after eighteen months on a 625 calorie daily deficit. Of course long before eighteen months was up he would have crossed the survivability BMI threshold in a downward direction, if he really had a 625 daily caloric deficit. Does this clarify the issue I am raising here? Either Leibel's assertion that BMR does not drop more than 15% is full of it. Or the mice experiments are full of it. Or my logic is full of it. Do we know which? Rodney. > > I don't think that mice metabolism is too different from humans. > Applying the Mifflin-St Jeor energy equations to 50%-size humans shows > that they need 60% of the nutrition of full-size humans, i.e., 40% CR, > the same as mice. See the bottom of my web page for the calculations: > > http://www.scientificpsychic.com/health/crondiet.html > > If you recall, in August of 2004 (Message 14018, What is CRON? - 18% > more food?), we had some discussions on this topic. I have been > trying to understand the paradox that 40%CR mice and rats eat 18% more > food per body weight than ad libitum rodents. I think that the > metabolic capacity decreases at a slower rate than body weight as the > food calories are restricted. Liebel's data basically confirms the > limit of ~15% found by Keys (Keys A, Brozek J, Henschel A, Mickelsen > O, HL. " The biology of human starvation " , Minneapolis: > University of Minneapolis Press, 1950.) > > Longevity may depend to some degree on the lowering of metabolic rate, > but also on other factors such as amount of adipose tissue, etc., and > everything is probably interrelated. The fact that higher CR rates > result in longer lifespans, even though metabolic rate bottoms out at > -15%, means that the lower metabolic rate is not the only factor for > longevity. > > Tony > > > --- In , " Rodney " <perspect1111@y...> wrote: > > > > Hi Tony: > > > > I haven't properly studied the article, just skimmed it very > > quickly. Perhaps I will get to it on the weekend. But mice must be > > different from humans then? > > > > When mice are restricted 40%, weight drops 50%. Now if their BMR > > drops only 15%, as Leibel appears to claim, then logically, the mice > > should shrivel up to nothing since they are burning up in BMR > > calories a lot more than they are taking in? In fact, though, quite > > the contrary, they thrive, being very energetic and live > > substantially longer. > > > > So, are mice different from humans in this respect? Or is there > > something faulty in Liebel's data - or in the mice data, of course - > > or, LOL, in my logic?! > > > > Rodney. > > > > -- In , " citpeks " <citpeks@y...> quoted: > > > > ........................... > > > RL: No. That is another very interesting point. When a person goes > > > down 10 percent in body weight, lean or obese their reduction in > > > energy expenditure is in the 15 percent range. If you take them down > > > by 20 percent, it doesn't get any more. So it appears that whatever > > > this defense mechanism is, if you want to look at it teleologically > > > like that, it kicks in quite early: 10 percent is enough to bring it > > > out. We don't know whether five percent is, because we've never > > tested > > > that small an increase in weight. But [energy expenditure] doesn't > > > reduce any further if you drop them 20 percent, 30 percent, or even > > as > > > much as 50 percent. > > > Quote Link to comment Share on other sites More sharing options...
Guest guest Posted December 8, 2005 Report Share Posted December 8, 2005 Hi Tony: Editorial correction: Please replace this: " When the exercise is added in there is a daily caloric deficit of 625 (the 1545 + 580 = 2125) that Leibel would have us believe are being expended minus the 1500 that we know are being consumed. " With: " When the exercise is added in there is a daily caloric deficit of 625 ...... the 2125 (1545 + 580) that Leibel would have us believe are being expended, minus the 1500 that we know are being consumed. " Rodney. > > > > > > Hi Tony: > > > > > > I haven't properly studied the article, just skimmed it very > > > quickly. Perhaps I will get to it on the weekend. But mice must > be > > > different from humans then? > > > > > > When mice are restricted 40%, weight drops 50%. Now if their BMR > > > drops only 15%, as Leibel appears to claim, then logically, the > mice > > > should shrivel up to nothing since they are burning up in BMR > > > calories a lot more than they are taking in? In fact, though, > quite > > > the contrary, they thrive, being very energetic and live > > > substantially longer. > > > > > > So, are mice different from humans in this respect? Or is there > > > something faulty in Liebel's data - or in the mice data, of > course - > > > or, LOL, in my logic?! > > > > > > Rodney. > > > > > > -- In , " citpeks " <citpeks@y...> > quoted: > > > > > > ........................... > > > > RL: No. That is another very interesting point. When a person > goes > > > > down 10 percent in body weight, lean or obese their reduction in > > > > energy expenditure is in the 15 percent range. If you take them > down > > > > by 20 percent, it doesn't get any more. So it appears that > whatever > > > > this defense mechanism is, if you want to look at it > teleologically > > > > like that, it kicks in quite early: 10 percent is enough to > bring it > > > > out. We don't know whether five percent is, because we've never > > > tested > > > > that small an increase in weight. But [energy expenditure] > doesn't > > > > reduce any further if you drop them 20 percent, 30 percent, or > even > > > as > > > > much as 50 percent. > > > > > > Quote Link to comment Share on other sites More sharing options...
Guest guest Posted December 8, 2005 Report Share Posted December 8, 2005 Hi Tony: Editorial correction: Please replace this: " When the exercise is added in there is a daily caloric deficit of 625 (the 1545 + 580 = 2125) that Leibel would have us believe are being expended minus the 1500 that we know are being consumed. " With: " When the exercise is added in there is a daily caloric deficit of 625 ...... the 2125 (1545 + 580) that Leibel would have us believe are being expended, minus the 1500 that we know are being consumed. " Rodney. > > > > > > Hi Tony: > > > > > > I haven't properly studied the article, just skimmed it very > > > quickly. Perhaps I will get to it on the weekend. But mice must > be > > > different from humans then? > > > > > > When mice are restricted 40%, weight drops 50%. Now if their BMR > > > drops only 15%, as Leibel appears to claim, then logically, the > mice > > > should shrivel up to nothing since they are burning up in BMR > > > calories a lot more than they are taking in? In fact, though, > quite > > > the contrary, they thrive, being very energetic and live > > > substantially longer. > > > > > > So, are mice different from humans in this respect? Or is there > > > something faulty in Liebel's data - or in the mice data, of > course - > > > or, LOL, in my logic?! > > > > > > Rodney. > > > > > > -- In , " citpeks " <citpeks@y...> > quoted: > > > > > > ........................... > > > > RL: No. That is another very interesting point. When a person > goes > > > > down 10 percent in body weight, lean or obese their reduction in > > > > energy expenditure is in the 15 percent range. If you take them > down > > > > by 20 percent, it doesn't get any more. So it appears that > whatever > > > > this defense mechanism is, if you want to look at it > teleologically > > > > like that, it kicks in quite early: 10 percent is enough to > bring it > > > > out. We don't know whether five percent is, because we've never > > > tested > > > > that small an increase in weight. But [energy expenditure] > doesn't > > > > reduce any further if you drop them 20 percent, 30 percent, or > even > > > as > > > > much as 50 percent. > > > > > > Quote Link to comment Share on other sites More sharing options...
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