This isn't the first study to show that our bodies adjust to fairly set caloric expenditure - the constrained total energy expenditure model isn't new, and Ponztner and his team aren't the first to advocate for it, but we should be clear that he is an advocate for it, and has been for a while.

Obviously, energy has to come from somewhere, so enough exercise will overcome any adaptations your body makes, but the current evidence seems to suggest that there is a lot of wiggle room for your body to cut energy expenditure to make up for any exercising you do. The evidence suggests this takes time, but it does also suggest that the 20 minutes on the bike daily that helped you drop some pounds at the start will not do much for your weight a year in.

I don't know if it's true or not, but when I first read one of the studies, it did make some intuitive sense to me - humans have spent much of their evolutionary history having to expend significant energy to procure food. If you had to walk 30,000 steps in a day to forage or hunt, it makes sense that limiting other movements while idle, etc., to help preserve energy stores would be beneficial.

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hermitcrab 2 days ago | parent [-]

My understanding is that the research shows that a highly active hunter gathering and an inactive office worker burn roughly the same number of calories per day. But I find that hard to believe. What is the office worker's body doing to make up the difference for all the movement and muscle contraction?

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wredcoll 2 days ago | parent | next [-]

Human bodies are highly efficient at certain movements, e.g. walking. There's also a complicated part of hunter gatherer life style where you don't know if you'll find something if you walk another mile, so often the response is to just... not do that.

Being able to have a life style where you're constantly expending energy, like training athletes do, really only works if you're guaranteed food, which is generally not how hunter gathering works.

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cthalupa 2 days ago | parent | prev [-]

Lots and lots (and lots) of small subconscious movements throughout the day. Many thousands of them. Moving your heard around, tilting it a bit, wiggling your toes, rolling your shoulders, scratching an itch, etc.

Anecdotally, I believe I have a personal example of the sort of thing that changes. I went from being ultra-sedentary to exercising 5+ days a week over the past year. My body had enough of these tics that they had long since passed over the subconscious and unnoticed level into "why the fuck do I keep bouncing my legs around all the time when sitting or in bed." Now, I never do. After years of trying, I stopped making any sort of intentional effort to stop - and even things like weighted blankets, etc., in the past did nothing.

Now, I just don't do it. I fidget less at my desk while working. I make a whole lot less 'random' movements for no discernible reason.

Add up enough of all these tiny things over the course of a day, things you probably don't even realize you're doing, and each tiny fraction of a calorie expended eventually pushes you to the levels you see with more regular exercise.

(Now, of course, exercise is hugely important for a variety of other health factors)

	▲	hermitcrab 2 days ago \| parent [-]
		Glad to hear that exercize has worked for you. >Add up enough of all these tiny things over the course of a day, things you probably don't even realize you're doing, and each tiny fraction of a calorie expended eventually pushes you to the levels you see with more regular exercise. Fidgeting will obviously burn some calories. But I find it hard to believe that fidgeting will burn the same amount of calories as sustained exersize. I have heard some suggestion that the extra energy is being burned at a cellular level (causing inflammation). But would be office work get hot if that was the case?