I would say we all suffer from a bit of computer addiction ha ha. As for me, I have a fairly short attention span for drafting legal documents so I pop in every few minutes to distract myself when I'm at work. I used to read an article in the New York Times every 10 minutes or so but now I come here more. Even weight is less depressing than the news sometimes.
That is what I do, a few minutes of work, a few minutes on here.
Or sometimes no work and all here, lol.
With regard to TomO's metabolism question, what do you think of the RMR tests they give? Do you know if they're considered accurate or not? I wonder how the RMR test (which gives a metabolic measure based on breathing into the machine for 10 mins) is affected by changes in metabolic rate from dieting or other issues.
I honestly don't know Claudia....
I'm sure it's a lot more accurate than taking your temp.... but in terms of specifics, I have no clue how accurate those kinds of tests are. I never looked into it.
Also, about our Leptin conversation, I thought this might be of interest to you; I had a pretty interesting conversation with Lyle McDonald yesterday, thanks to you. I was trying to draw any new information he had out... which can be tough at times.
It went like this:
Steve in
bold, Lyle not:
Is it safe to assume that Leptin resistance is commonplace among overweight/obese individuals?
thta's the standard interpretation yes.
Also, how similar are the characteristics of Leptin resistance when compared to low leptin.... i.e., the same starvation signaling?
probably, in the same way someone with isufficient insulin sees simlar effects to someone who's body can't respond to insulin
Lastly, has there been anything presented in research or empirically to suggest a way to solve leptin resistance, aside from losing fat?
not really. long term fish oils might help, it does in animals anyhow. exercise might as well, at least acutely
So telling a fat person to simply 'suck it up' since all dieters experience hunger pangs may not be totally right?
I mean, if, even at an uber-high weight, someone can be experiencing the same sort of starvation 'backlash' as a physique competitor leaning down, it's not as simple* as just eat less and move more. They could be experiencing hunger pangs above the norm associated with dieting. They could be experiencing a metabolic slowdown big enough to impact their weight loss, even though they are so overweight. And worse yet, the obese individual can't combat it with things such as refeeds and breaks since the starvation signaling isn't being caused by a reduction in leptin.
*Well it is that simple.... but it's just a bumpier road for a 250+ lb woman to lose than it might be for a 150 lb woman.
potentially
although what little i can think of looking at hunger during dieting while obese doesn't show problems until they cross a certain threshold of weight/leptin levels. at least not significantly
as well, BMR is always higher in fatter people than leaner.
and, generally speaking, fatter people lose more easily/faster than leaner in any case.
even with leptin resistance, when levels are that high, there is still a signal just by sheer dint of the amount present
So are you saying that after a certain amount of weight is lost, at this threshold is when the starvation signaling could really kick in?
And I'm assuming that if this is the case.... this threshold occurs while the individual is still overweight?
And wrt the BMR statement being higher in big people, you're right, so technically, they have more room to play with.....
Meaning, if their maintenance is 4000 and they're eating 2000, the metabolism is not going to drop the full 2000 to halt weight loss.
one of the ideas that was being thrown around at one point was that leptin transport into the brain would saturate about a certain level, as I recall it was about 20-25 (whatever units leptin is in, probably ng/dl or something). in one study, subjects were followed over a good bit of weight loss and appetite was tracked. appetite didn't start to significantly go up until they came below a certain bodyweight/BF%age threshold. right about the time leptin dropped below the theorized saturation point. And they were still pretty fat. I'm thinking still around 30% bodyfat but don't hold me to that unless I can track down the paper. which I can't right now.
leptin is thought to act most effectively at fairly low concentrations (again, my memory says it's about 1 which is like low teens bodyfat for men, but I won't swear to it unless I can cite it).
as well, I think this explains the studies that have found an adaptive component to metabolic rate (subjects were relaively leaner and below the leptin threshold point) versus those that dont (subjects were much fatter and were not below that point). that's my interepretation anyhow.
wrt what you say about having 'more room to play with', I think the massive weekly weight losses on the biggest loser are kind of interesting in this regards. you have super fatties losing 10-20 lbs/week for multiple weekss by really cutting calories hard and training like maniacs. if there's metabolic slowing going on, either it's too small to be relevant or it's just being overwhelmed by the sheer size of the deficit.
I'd love to see that paper, if anyone else has it.
And if this is the case, theoretically, this person is damned if they do, damned if the don't. I mean, they either remain fat, relatively speaking although smaller than they were, or they battle perpetual starvation symptoms, struggling to reach a more acceptable weight.
Assuming you are correct that the adaptations kicked in around 30%BF, they're relatively lean to their former selves, but they're still fat.
I guess what I'm getting at is, it's hypothesized that an over-abundance of fat leads to and over-abundance of leptin, which in itself, leads to complications such as leptin resistance and saturation of the BBB. If I'm reading you correctly, this leads to a permanently elevated threshold, leaving the person at a much higher BF% while still experiencing starvation symtoms when compared to your average dieter trying to lose 20 lbs or so.
hence the huge interest in developing drugs to fix some of the problems.
life is a continuum and this is no exception. yes, appetite started to increase at that point (as I recall) and would probably get worse with further weight loss. leaving two options: suck it up or stay fat.
wrt the permanently elevated threshold, that idea has been thrown around and some animal work suggests that it can happen. it's impossible to determine exactly in humans what is going on in this regards. but it is currently being argued that, rather than try to treat existing obesity, it'd be better to simply prevent it from occurring (by focusing on kids).
wrt to it being harder for continued weight loss for the bigger person compared with the smaller person, relatively speaking, perhaps. they will be hungrier than when they were fat and happy and metabolism will decrease somewhat relative to where they were. in no way does that eliminate the potential for continued fat/weight loss, it simlpy makes it more difficult.
Do you think the drugs are a long way off?
And I guess it's safe to assume that some overweight individuals don't have the same degree of difficulty associated with the leptin resistance. Some big people seem to simply decide to lose the weight, control their calories, start moving a bit more, and presto, they're a different person after a year or two.
Yea, I understand that impossibility of factoring out the psychological individuality of things that obviously play a massive role too.
for giggles the other day I priced injectable leptin
still about $500 per day for an effective dose, no clue what hte intranasal stuff would run
i've seen nothing drug wise addressing leptin resistance even in the pipeline so I wouldn't expect anything to show up for years
Lyle:
