MrRippedZilla
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Long-term persistence of adaptive thermogenesis when maintaining a reduced body weight
Full paper: Long-term persistence of adaptive thermogenesis in subjects who have maintained a reduced body weight
BACKGROUND:
After weight loss, total energy expenditure -- in particular, energy expenditure at low levels of physical activity -- is lower than predicted by actual changes in body weight and composition. An important clinical issue is whether this reduction, which predisposes to weight regain, persists over time.
OBJECTIVE:
We aimed to determine whether this disproportionate reduction in energy expenditure persists in persons who have maintained a body-weight reduction of > or =10% for >1 y.
DESIGN:
Seven trios of sex- and weight-matched subjects were studied in an in-patient setting while receiving a weight-maintaining liquid formula diet of identical composition.
Each trio consisted of a subject at usual weight (Wt(initial)), a subject maintaining a weight reduction of > or =10% after recent (5-8 wk) completion of weight loss (Wt(loss-recent)), and a subject who had maintained a documented reduction in body weight of >10% for >1 y (Wt(loss-sustained)).
Twenty-four-hour total energy expenditure (TEE) was assessed by precise titration of fed calories of a liquid formula diet necessary to maintain body weight. Resting energy expenditure (REE) and the thermic effect of feeding (TEF) were measured by indirect calorimetry. Nonresting energy expenditure (NREE) was calculated as NREE = TEE - (REE +TEF).
RESULTS:
TEE, NREE, and (to a lesser extent) REE were significantly lower in the Wt(loss-sustained) and Wt(loss-recent) groups than in the Wt(initial) group. Differences from the Wt(initial) group in energy expenditure were qualitatively and quantitatively similar after recent and sustained weight loss.
CONCLUSION:
Declines in energy expenditure favoring the regain of lost weight persist well beyond the period of dynamic weight loss.
Break down...
Methodology
"Adaptive thermogenesis" is the scientific term for what some call metabolic adaption or metabolic damage (usually by the clueless).
This is one of a small number of studies looking to see just how metabolically disadvantaged dieters, trying to maintain 10%+ weight loss, are in the long term because as most of you should know - losing weight isn't the hard part, maintaining it is.
The authors took both obese & non-obese subjects from their own previously conducted trials looking into energy metabolism before/after weight loss that was conducted at an in-patient setting.
An in-patient means keeping all subjects in a clinical research center. This allows the researchers to monitor physical activity, weight, subject compliance and diet (subjects were given a liquid formula diet only) - something that simply isn't possible with out-patient settings (where you give people instructions and then they go about their lives in the normal manner while you hope that they document everything accurately).
The subjects' physical activity was limited and therefore the results cannot be automatically extrapolated to apply to most of us (people who lift). And, obviously, the disadvantage of the living in a lab is that it doesn't reflect the free-living conditions of reality - an important point considering the huge impact our environment has on our body comp goals.
Results & discussion
The major finding, and why this is such an important paper, was that significant declines in total energy expenditure (TEE), non-resting energy expenditure (NREE) and, to a lesser extent, resting energy expenditure (REE) that occur when dieting did NOT go away when subjects attempted to maintain the weight reduction - even if weeks or years had past.
It's a permanent adaptation and as the authors put it:
"bioenergetic responses to maintenance of a reduced body weight do not wane with time."
Based on their previous data, the authors confirmed the reality that biological systems regulating energy intake/output during post-weight loss maintenance act to favor weight re-gain.
To put it simply, someone who is naturally 12%bf will ALWAYS find it easier to stay in that condition compared to someone who had to diet down to that level regardless of the amount of time that may have passed since the dieting phase.
The only "natural" way to completely reverse these adaptations is to simply regain the lost weight. Let me be very clear, reverse dieting or anything even remotely related to it is complete bullshit and will NOT prevent or help you recover from these adaptations.
Many of these adaptations can also be reversed by restoring leptin to its pre-weight loss level but since synthetic leptin is very difficult to find & extremely expensive (it makes GH look cheap), it isn't a realistic option for us.
Other drugs such like AAS, T3, Insulin, etc do act to counteract some of the side effects of lower leptin levels (hypoleptinemia) and do a lot to help maintain energy expenditure but the appetite regulation side of the equation is still left relatively unsolved.
I have ideas about how to go about fixing all of this but without getting too geeky I'll just say that its a work in progress and the easiest answer is still to simply make Leptin a more accessible drug (financially, helping people maintain a lower weight doesn't seem to be a decent incentive for most companies...make of that what you will).
As for proactive measures to minimize the effect of this adaptation outside of drug use, I do recommend not going OCD with the cardio and implementing periodic refeeds with an emphasis on carb intake. Diet & training optimization (lifting helps) will reduce the overall impact of these adaptions but not prevent them completely - keep that in mind.
For those interested in the evidence behind these approaches, its based off of critical thinking on my part (since no study directly examines the impact of this stuff to a good enough level) drawn from data like this:
Changes in Energy Expenditure Resulting from Altered Body Weight
Low-dose leptin reverses skeletal muscle, autonomic, and neuroendocrine adaptations to maintenance of reduced weight
Effects of changes in body weight on carbohydrate metabolism, catecholamine excretion, and thyroid function
The take home point is that maintaining weight loss beyond what your body is comfortable with (set point) is a very tough battle with your body actively fighting against you all the way. It sucks
Full paper: Long-term persistence of adaptive thermogenesis in subjects who have maintained a reduced body weight
BACKGROUND:
After weight loss, total energy expenditure -- in particular, energy expenditure at low levels of physical activity -- is lower than predicted by actual changes in body weight and composition. An important clinical issue is whether this reduction, which predisposes to weight regain, persists over time.
OBJECTIVE:
We aimed to determine whether this disproportionate reduction in energy expenditure persists in persons who have maintained a body-weight reduction of > or =10% for >1 y.
DESIGN:
Seven trios of sex- and weight-matched subjects were studied in an in-patient setting while receiving a weight-maintaining liquid formula diet of identical composition.
Each trio consisted of a subject at usual weight (Wt(initial)), a subject maintaining a weight reduction of > or =10% after recent (5-8 wk) completion of weight loss (Wt(loss-recent)), and a subject who had maintained a documented reduction in body weight of >10% for >1 y (Wt(loss-sustained)).
Twenty-four-hour total energy expenditure (TEE) was assessed by precise titration of fed calories of a liquid formula diet necessary to maintain body weight. Resting energy expenditure (REE) and the thermic effect of feeding (TEF) were measured by indirect calorimetry. Nonresting energy expenditure (NREE) was calculated as NREE = TEE - (REE +TEF).
RESULTS:
TEE, NREE, and (to a lesser extent) REE were significantly lower in the Wt(loss-sustained) and Wt(loss-recent) groups than in the Wt(initial) group. Differences from the Wt(initial) group in energy expenditure were qualitatively and quantitatively similar after recent and sustained weight loss.
CONCLUSION:
Declines in energy expenditure favoring the regain of lost weight persist well beyond the period of dynamic weight loss.
Break down...
Methodology
"Adaptive thermogenesis" is the scientific term for what some call metabolic adaption or metabolic damage (usually by the clueless).
This is one of a small number of studies looking to see just how metabolically disadvantaged dieters, trying to maintain 10%+ weight loss, are in the long term because as most of you should know - losing weight isn't the hard part, maintaining it is.
The authors took both obese & non-obese subjects from their own previously conducted trials looking into energy metabolism before/after weight loss that was conducted at an in-patient setting.
An in-patient means keeping all subjects in a clinical research center. This allows the researchers to monitor physical activity, weight, subject compliance and diet (subjects were given a liquid formula diet only) - something that simply isn't possible with out-patient settings (where you give people instructions and then they go about their lives in the normal manner while you hope that they document everything accurately).
The subjects' physical activity was limited and therefore the results cannot be automatically extrapolated to apply to most of us (people who lift). And, obviously, the disadvantage of the living in a lab is that it doesn't reflect the free-living conditions of reality - an important point considering the huge impact our environment has on our body comp goals.
Results & discussion
The major finding, and why this is such an important paper, was that significant declines in total energy expenditure (TEE), non-resting energy expenditure (NREE) and, to a lesser extent, resting energy expenditure (REE) that occur when dieting did NOT go away when subjects attempted to maintain the weight reduction - even if weeks or years had past.
It's a permanent adaptation and as the authors put it:
"bioenergetic responses to maintenance of a reduced body weight do not wane with time."
Based on their previous data, the authors confirmed the reality that biological systems regulating energy intake/output during post-weight loss maintenance act to favor weight re-gain.
To put it simply, someone who is naturally 12%bf will ALWAYS find it easier to stay in that condition compared to someone who had to diet down to that level regardless of the amount of time that may have passed since the dieting phase.
The only "natural" way to completely reverse these adaptations is to simply regain the lost weight. Let me be very clear, reverse dieting or anything even remotely related to it is complete bullshit and will NOT prevent or help you recover from these adaptations.
Many of these adaptations can also be reversed by restoring leptin to its pre-weight loss level but since synthetic leptin is very difficult to find & extremely expensive (it makes GH look cheap), it isn't a realistic option for us.
Other drugs such like AAS, T3, Insulin, etc do act to counteract some of the side effects of lower leptin levels (hypoleptinemia) and do a lot to help maintain energy expenditure but the appetite regulation side of the equation is still left relatively unsolved.
I have ideas about how to go about fixing all of this but without getting too geeky I'll just say that its a work in progress and the easiest answer is still to simply make Leptin a more accessible drug (financially, helping people maintain a lower weight doesn't seem to be a decent incentive for most companies...make of that what you will).
As for proactive measures to minimize the effect of this adaptation outside of drug use, I do recommend not going OCD with the cardio and implementing periodic refeeds with an emphasis on carb intake. Diet & training optimization (lifting helps) will reduce the overall impact of these adaptions but not prevent them completely - keep that in mind.
For those interested in the evidence behind these approaches, its based off of critical thinking on my part (since no study directly examines the impact of this stuff to a good enough level) drawn from data like this:
Changes in Energy Expenditure Resulting from Altered Body Weight
Low-dose leptin reverses skeletal muscle, autonomic, and neuroendocrine adaptations to maintenance of reduced weight
Effects of changes in body weight on carbohydrate metabolism, catecholamine excretion, and thyroid function
The take home point is that maintaining weight loss beyond what your body is comfortable with (set point) is a very tough battle with your body actively fighting against you all the way. It sucks
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