4 ms·

I feel like this is a misinterpretation of the findings. I think the finding is that your metabolic rate doesn't change much if you are very active but you stil

I feel like this is a misinterpretation of the findings. I think the finding is that your metabolic rate doesn't change much if you are very active but you still burn a lot more calories doing the activity. Physically moving weight around (weightlifting) or moving your body for tens of miles (marathon runner) requires a large amount of energy, your body can't just take this from other processes, it needs more input or it will have to burn the fat. People who train any sport need to eat a lot more too maintain their weight.

Tade0 2y ago
Nope. It's actually "no real difference between active and sedentary people". Here's a podcast with one of the researchers who studied this: https://theproof.com/rethinking-diet-exercise-with-herman-pontzer-phd/ https://theproof.com/rethinking-diet-exercise-with-herman-po... The gist is that he went to a modern hunter-gatherer community, studied their activities and measured their energy expenditure. To his incredulity, the results indicated that these very active people use as much energy as their sedentary counterparts living in civilisation. Initial conclusion was that there must have been a mistake somewhere, but the same measurement using a different method yielded the same results.
- episteme 2y ago
  That makes me believe that what they were measuring was not energy expenditure, how can that be the case without breaking the first law of thermodynamics?
  - Tade0 2y ago
    Like I said before: there's a fixed energy budget and you only get to decide what you spend it on, not how much you have. There's less than 10% of wiggle room - the difference between utterly inactive people and those who get at least a little bit of exercise. No real difference between very active people and the former. Similar studies on rats showed that increased activity reduces processes like inflammation, healing of wounds and production of reproductive hormones like estrogen. Essentially our digestive systems are already doing their best. There was an additional study in cooperation with several zoos which showed that other primates work the same. Humans have actually a pretty active metabolism in comparison, as it burns an average of 400kcal more.
- plorkyeran 2y ago
  The Hadza study has some interesting implications, but a lot of the reporting on it has massively blown it out of proportion. They walk 4-7 miles per day while burning a total of an average of 2500 calories. That's fewer calories than expected, but not actually by all that much. Two hours of walking per day sounds like a lot compared to an office worker who does not engage in any sort of physical activity, but it's quite small compared to what people who work physically demanding jobs or do any meaningful amount of cardio training get.
  - Tade0 2y ago
    They don't just walk. Their whole lives are physically demanding as they do everything by hand. The men hunt, the women forage. Everyone crafts their tools. Also it's not just this study. Research on this actually started in the 1980s when the double labelled water method became practical - unfortunately it's still massively expensive. All in all there's a much larger body of research indicating that exercise is not effective at controlling weight. The Hadza study at least gives some clues and indicates that there's something we're missing and this mechanistic approach to metabolism where you can just coax it into burning more is a model that doesn't reflect reality.

Tade0 2y ago

Nope. It's actually "no real difference between active and sedentary people". Here's a podcast with one of the researchers who studied this: https://theproof.com/rethinking-diet-exercise-with-herman-pontzer-phd/ https://theproof.com/rethinking-diet-exercise-with-herman-po... The gist is that he went to a modern hunter-gatherer community, studied their activities and measured their energy expenditure. To his incredulity, the results indicated that these very active people use as much energy as their sedentary counterparts living in civilisation. Initial conclusion was that there must have been a mistake somewhere, but the same measurement using a different method yielded the same results.

episteme 2y ago
That makes me believe that what they were measuring was not energy expenditure, how can that be the case without breaking the first law of thermodynamics?
- Tade0 2y ago
  Like I said before: there's a fixed energy budget and you only get to decide what you spend it on, not how much you have. There's less than 10% of wiggle room - the difference between utterly inactive people and those who get at least a little bit of exercise. No real difference between very active people and the former. Similar studies on rats showed that increased activity reduces processes like inflammation, healing of wounds and production of reproductive hormones like estrogen. Essentially our digestive systems are already doing their best. There was an additional study in cooperation with several zoos which showed that other primates work the same. Humans have actually a pretty active metabolism in comparison, as it burns an average of 400kcal more.
plorkyeran 2y ago
The Hadza study has some interesting implications, but a lot of the reporting on it has massively blown it out of proportion. They walk 4-7 miles per day while burning a total of an average of 2500 calories. That's fewer calories than expected, but not actually by all that much. Two hours of walking per day sounds like a lot compared to an office worker who does not engage in any sort of physical activity, but it's quite small compared to what people who work physically demanding jobs or do any meaningful amount of cardio training get.
- Tade0 2y ago
  They don't just walk. Their whole lives are physically demanding as they do everything by hand. The men hunt, the women forage. Everyone crafts their tools. Also it's not just this study. Research on this actually started in the 1980s when the double labelled water method became practical - unfortunately it's still massively expensive. All in all there's a much larger body of research indicating that exercise is not effective at controlling weight. The Hadza study at least gives some clues and indicates that there's something we're missing and this mechanistic approach to metabolism where you can just coax it into burning more is a model that doesn't reflect reality.