Why thinking hard makes us feel tired

Re:Why thinking hard makes us feel tired by dekhn on Thursday November 16, 2023 @11:40PM (#38299651)

Do people who burn 3500 calories weigh one pound less? Are you sure? From what I can tell, weight changes happen only partly due to CO2 exchange and partly due to rates of consumption and excretion.

The biophysical origin (I'm a biophysicist) of weight change as a function of energy use, eating and excretion is a bit more complicated than that.

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Re:Why thinking hard makes us feel tired by mock-possum on Friday November 17, 2023 @03:21AM (#38300909)

So wait if I fasted for two days, could I responsibly expect to come out the other side one pound lighter? That’d be a roughly 3600 calorie deficit.

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Re:Why thinking hard makes us feel tired by devmor on Monday November 20, 2023 @02:53PM (#38353570)

Yes.

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Re:Why thinking hard makes us feel tired by insanitybit on Friday November 17, 2023 @08:38AM (#38303337)

Assuming that they burned purely fat for energy, what else could it be? Are you saying that it's not just fat being burned, or that 'burning' the fat is not going from '1' to '0' in terms of weight?

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Re:Why thinking hard makes us feel tired by devmor on Monday November 20, 2023 @02:56PM (#38353616)

Give or take, yes.

Like you said, it’s a bit more complicated than that and every body is different. But burning roughly 3500 calories will result in the body weighing roughly 1lb less (accounting for food and water intake and loss).

If it didn’t work this way, every bodybuilder and fitness enthusiast on the planet would have a very different approach to their diet.

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