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It's kind of shouting into the void but I always wanted to try to teach high school physics starting from energies rather than forces/velocities/other vectors... And the easiest places where people run into energies are light bulb wattages and nutrition facts, and the latter always seemed more interesting than the former, so the idea was “The Biophysics of Weight Loss” as a first physics course. As an example of how this looks a bit different to a physicist, most people go to an online calculator to get their TDEE or RMR, some measure of how much energy per day passes out of their body. If you're a physicist, you can't help but measure this at two different weights, current and target. So that gives you a slope, a delta: kilocalories per day per kilogram of fat lost. Except there is also a rough measure of how many kilocalories to lose to lose a kg of fat, so in dimensional analysis terms, this is really just a time constant. I forget the exact amount but it works out to something like nine months or a year or so. And then you realize that that's a half life. You choose a lifestyle, you start living as if your weight were W, then after a year you will get halfway there, after another year you'll get halfway closer, and so on, and so on. But that's not how anybody thinks on a diet. They are thinking, I'm going to intervene, get my life under control, then I can return to the lifestyle I had before but without the weight. But what you are describing is a severe lifestyle shift, “I became a marathon runner and my friends are all marathon runners and that is our new lifestyle.” Polar opposite of intervention. But it's also, there's a selection bias. If the actual cause is depression related, and marathoning worked because it gave a new sense of purpose and self, how would you notice? You spend all this time on caloric output, that's trying to treat it like a linear system. When the circuit has transistors and op amps, that's not how you analyze it. |